diff --git a/1ano/2semestre/poo/src/aula07/ex1/Circle.java b/1ano/2semestre/poo/src/aula07/ex1/Circle.java
new file mode 100644
index 0000000..d83306b
--- /dev/null
+++ b/1ano/2semestre/poo/src/aula07/ex1/Circle.java
@@ -0,0 +1,43 @@
+package aula07.ex1;
+
+public class Circle extends Shape {
+    private double radius;
+
+    public Circle(double radius) {
+        if (radius <= 0)
+            throw new IllegalArgumentException("Sizes must be positive.");
+        this.radius = radius;
+    }
+
+    public double getRadius() {
+        return this.radius;
+    }
+
+    public void setRadius(double radius) {
+        if (radius <= 0)
+            throw new IllegalArgumentException("Sizes must be positive.");
+        this.radius = radius;
+    }
+
+    @Override
+    public double getArea() {
+        return Math.PI * Math.pow(this.radius, 2);
+    }
+
+    @Override
+    public double getPerimeter() {
+        return 2 * Math.PI * this.radius;
+    }
+
+    @Override
+    public boolean equals(Shape s2) {
+        if (s2 instanceof Circle s2Circ)
+            return this.radius == s2Circ.radius;
+        return false;
+    }
+
+    @Override
+    public String toString() {
+        return "Circle with radius " + this.radius;
+    }
+}
diff --git a/1ano/2semestre/poo/src/aula07/ex1/Rectangle.java b/1ano/2semestre/poo/src/aula07/ex1/Rectangle.java
new file mode 100644
index 0000000..ca50d04
--- /dev/null
+++ b/1ano/2semestre/poo/src/aula07/ex1/Rectangle.java
@@ -0,0 +1,46 @@
+package aula07.ex1;
+
+public class Rectangle extends Shape {
+    public double side1;
+    public double side2;
+
+    public Rectangle(double side1, double side2) {
+        if (!(side1 > 0 && side2 > 0))
+            throw new IllegalArgumentException("Sizes must be positive.");
+        this.side1 = side1;
+        this.side2 = side2;
+    }
+
+    public double[] getSides() {
+        return new double[] {this.side1, this.side2};
+    }
+
+    public void setSides(double side1, double side2) {
+        if (!(side1 > 0 && side2 > 0))
+            throw new IllegalArgumentException("Sizes must be positive.");
+        this.side1 = side1;
+        this.side2 = side2;
+    }
+
+    @Override
+    public boolean equals(Shape s2) {
+        if (s2 instanceof Rectangle s2Rect)
+            return this.side1 == s2Rect.side1 && this.side2 == s2Rect.side2;
+        return false;
+    }
+
+    @Override
+    public String toString() {
+        return "Rectangle with sides " + this.side1 + ", " + this.side2;
+    }
+
+    @Override
+    public double getArea() {
+        return this.side1 * this.side2;
+    }
+
+    @Override
+    public double getPerimeter() {
+        return 2 * (this.side1 + this.side2);
+    }
+}
diff --git a/1ano/2semestre/poo/src/aula07/ex1/Shape.java b/1ano/2semestre/poo/src/aula07/ex1/Shape.java
new file mode 100644
index 0000000..ed19ada
--- /dev/null
+++ b/1ano/2semestre/poo/src/aula07/ex1/Shape.java
@@ -0,0 +1,8 @@
+package aula07.ex1;
+
+public abstract class Shape {
+    public abstract boolean equals(Shape c2);
+    public abstract String toString();
+    public abstract double getArea();
+    public abstract double getPerimeter();
+}
diff --git a/1ano/2semestre/poo/src/aula07/ex1/Triangle.java b/1ano/2semestre/poo/src/aula07/ex1/Triangle.java
new file mode 100644
index 0000000..c41280f
--- /dev/null
+++ b/1ano/2semestre/poo/src/aula07/ex1/Triangle.java
@@ -0,0 +1,50 @@
+package aula07.ex1;
+
+public class Triangle extends Shape {
+    private double side1;
+    private double side2;
+    private double side3;
+
+    public Triangle(double side1, double side2, double side3) {
+        if (!(side1 > 0 && side2 > 0 && side3 > 0))
+            throw new IllegalArgumentException("Sizes must be positive.");
+        this.side1 = side1;
+        this.side2 = side2;
+        this.side3 = side3;
+    }
+
+    public double[] getSides() {
+        return new double[] {this.side1, this.side2, this.side3};
+    }
+
+    public void setSides(double side1, double side2, double side3) {
+        if (!(side1 > 0 && side2 > 0 && side3 > 0))
+            throw new IllegalArgumentException("Sizes must be positive.");
+        this.side1 = side1;
+        this.side2 = side2;
+        this.side3 = side3;
+    }
+
+    @Override
+    public boolean equals(Shape s2) {
+        if (s2 instanceof Triangle s2Triang)
+            return this.side1 == s2Triang.side1 && this.side2 == s2Triang.side2 && this.side3 == s2Triang.side3;
+        return false;
+    }
+
+    @Override
+    public String toString() {
+        return "Triangle with sides " + this.side1 + ", " + this.side2 + ", " + this.side3;
+    }
+
+    @Override
+    public double getArea() {
+        double p = this.getPerimeter() / 2;
+        return Math.sqrt(p * (p - this.side1) * (p - this.side2) * (p - this.side3));
+    }
+
+    @Override
+    public double getPerimeter() {
+        return this.side1 + this.side2 + this.side3;
+    }
+}
diff --git a/1ano/2semestre/poo/src/aula07/ex2/Date.java b/1ano/2semestre/poo/src/aula07/ex2/Date.java
new file mode 100644
index 0000000..1d544d7
--- /dev/null
+++ b/1ano/2semestre/poo/src/aula07/ex2/Date.java
@@ -0,0 +1,34 @@
+package aula07.ex2;
+
+public abstract class Date {
+    public abstract int getAbsDay();
+    public abstract int getDay();
+    public abstract int getMonth();
+    public abstract int getYear();
+    public abstract void increment();
+    public abstract void decrement();
+    public abstract void addDays(int days);
+    public abstract void removeDays(int days);
+
+
+    public static int monthDays(int month, int year) {
+        if (!validMonth(month))
+            return -1;
+        int[] daysPerMonth = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
+        if (month == 2 && isLeapYear(year))
+            return 29;
+        return daysPerMonth[month - 1];
+    }
+
+    public static boolean validMonth(int month) {
+        return month >= 1 && month <= 12;
+    }
+
+    public static boolean validDate(int day, int month, int year) {
+        return day >= 1 && day <= monthDays(month, year);
+    }
+
+    public static boolean isLeapYear(int year) {
+        return year % 100 == 0 ? year % 400 == 0 : year % 4 == 0;
+    }
+}
diff --git a/1ano/2semestre/poo/src/aula07/ex2/DateND.java b/1ano/2semestre/poo/src/aula07/ex2/DateND.java
new file mode 100644
index 0000000..cd4b35a
--- /dev/null
+++ b/1ano/2semestre/poo/src/aula07/ex2/DateND.java
@@ -0,0 +1,104 @@
+package aula07.ex2;
+
+import java.util.Objects;
+
+public class DateND extends Date {
+    private int absDay;
+
+    public DateND(int absDay) {
+        set(absDay);
+    }
+
+    public void set(int absDay) {
+        if (absDay <= 0)
+            throw new IllegalArgumentException("Absolute day must be positive!");
+        this.absDay = absDay;
+    }
+
+    @Override
+    public int getAbsDay() {
+        return this.absDay;
+    }
+
+    private int[] getYMD() {
+        int[] date = new int[3];
+
+        int tempAbsDay = this.absDay;
+        int year = 1999;
+        while (tempAbsDay > 0) {
+            year++;
+            tempAbsDay -= isLeapYear(year) ? 366 : 365;
+        }
+        date[2] = year;
+        tempAbsDay += isLeapYear(year) ? 366 : 365;
+
+        int month = 0;
+        while (tempAbsDay > 0) {
+            month++;
+            tempAbsDay -= monthDays(month, year);
+        }
+        date[1] = month;
+        tempAbsDay += monthDays(month, year);
+        date[0] = tempAbsDay;
+
+        return date;
+    }
+
+    @Override
+    public int getDay() {
+        return this.getYMD()[0];
+    }
+
+    @Override
+    public int getMonth() {
+        return this.getYMD()[1];
+    }
+
+    @Override
+    public int getYear() {
+        return this.getYMD()[2];
+    }
+
+    @Override
+    public void increment() {
+        this.absDay++;
+    }
+
+    @Override
+    public void decrement() {
+        this.absDay--;
+    }
+
+    @Override
+    public void addDays(int days) {
+        for (int i = 0; i < days; i++)
+            this.increment();
+    }
+
+    @Override
+    public void removeDays(int days) {
+        if (days > this.absDay)
+            this.absDay = 0;
+        else
+            for (int i = 0; i < days; i++)
+                this.decrement();
+    }
+
+    @Override
+    public String toString() {
+        return String.format("Date: %d past 01-01-2000", this.absDay);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        DateND dateND = (DateND) o;
+        return absDay == dateND.absDay;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(absDay);
+    }
+}
diff --git a/1ano/2semestre/poo/src/aula07/ex2/DateTest.java b/1ano/2semestre/poo/src/aula07/ex2/DateTest.java
new file mode 100644
index 0000000..2d1c7b9
--- /dev/null
+++ b/1ano/2semestre/poo/src/aula07/ex2/DateTest.java
@@ -0,0 +1,56 @@
+package aula07.ex2;
+
+import java.util.Scanner;
+
+public class DateTest {
+    public static void main(String[] args) {
+        Scanner sin = new Scanner(System.in);
+
+        while (true) {
+            System.out.print("Class to test (0-Quit;1-DateYMD;2-DateND): ");
+            String option = sin.nextLine();
+
+            switch (option) {
+                case "0" -> {
+                    sin.close();
+                    System.exit(0);
+                }
+                case "1" -> {
+                    System.out.print("Day: ");
+                    int day = Integer.parseInt(sin.nextLine());
+                    System.out.print("Month: ");
+                    int month = Integer.parseInt(sin.nextLine());
+                    System.out.print("Year: ");
+                    int year = Integer.parseInt(sin.nextLine());
+
+                    DateYMD date = new DateYMD(day, month, year);
+                    System.out.printf("Initial date: %s%n%n", date);
+                    System.out.printf("Absolute day: %d%n", date.getAbsDay());
+                    System.out.println("Adding 7 days...");
+                    date.addDays(7);
+                    System.out.printf("New absolute day: %d%n", date.getAbsDay());
+                    System.out.println("Removing 534 days...");
+                    date.removeDays(534);
+                    System.out.printf("New absolute day: %d%n", date.getAbsDay());
+                    System.out.println("Final date: " + date);
+                }
+                case "2" -> {
+                    System.out.print("Days past past 01-01-2000: ");
+                    int days = Integer.parseInt(sin.nextLine());
+
+                    DateND date = new DateND(days);
+                    System.out.printf("Initial date: %s%n%n", date);
+                    System.out.printf("YMD date: %s%n", new DateYMD(date.getDay(), date.getMonth(), date.getYear()));
+                    System.out.println("Adding 74 days...");
+                    date.addDays(74);
+                    System.out.printf("New YMD date: %s%n", new DateYMD(date.getDay(), date.getMonth(), date.getYear()));
+                    System.out.println("Removing 612 days...");
+                    date.removeDays(612);
+                    System.out.printf("New YMD date: %s%n", new DateYMD(date.getDay(), date.getMonth(), date.getYear()));
+                    System.out.println("Final date: " + date);
+                }
+                default -> System.out.println("Invalid option.");
+            }
+        }
+    }
+}
diff --git a/1ano/2semestre/poo/src/aula07/ex2/DateYMD.java b/1ano/2semestre/poo/src/aula07/ex2/DateYMD.java
new file mode 100644
index 0000000..e946917
--- /dev/null
+++ b/1ano/2semestre/poo/src/aula07/ex2/DateYMD.java
@@ -0,0 +1,111 @@
+package aula07.ex2;
+
+import java.util.Objects;
+
+public class DateYMD extends Date {
+    private int day;
+    private int month;
+    private int year;
+
+    public DateYMD(int day, int month, int year) {
+        set(day, month, year);
+    }
+
+    public void set(int day, int month, int year) {
+        if (!validDate(day, month, year))
+            throw new IllegalArgumentException("Invalid date");
+        this.day = day;
+        this.month = month;
+        this.year = year;
+    }
+
+    @Override
+    public int getAbsDay() {
+        int absDay = 0;
+        for (int i = 2000; i < this.year; i++) {
+            if (isLeapYear(i))
+                absDay += 366;
+            else
+                absDay += 365;
+        }
+        for (int i = 1; i < this.month; i++) {
+            absDay += monthDays(i, this.year);
+        }
+        return absDay + this.day;
+    }
+
+    @Override
+    public int getDay() {
+        return this.day;
+    }
+
+    @Override
+    public int getMonth() {
+        return this.month;
+    }
+
+    @Override
+    public int getYear() {
+        return this.year;
+    }
+
+    @Override
+    public void increment() {
+        if (this.day < monthDays(this.month, this.year))
+            this.day++;
+        else {
+            this.day = 1;
+            if (this.month < 12)
+                this.month++;
+            else {
+                this.month = 1;
+                this.year++;
+            }
+        }
+    }
+
+    @Override
+    public void decrement() {
+        if (this.day > 1)
+            this.day--;
+        else {
+            this.day = monthDays(this.month == 1 ? 12 : this.month-1, this.year);
+            if (this.month > 1)
+                this.month--;
+            else {
+                this.month = 12;
+                this.year--;
+            }
+        }
+    }
+
+    @Override
+    public void addDays(int days) {
+        for (int i = 0; i < days; i++)
+            this.increment();
+    }
+
+    @Override
+    public void removeDays(int days) {
+        for (int i = 0; i < days; i++)
+            this.decrement();
+    }
+
+    @Override
+    public String toString() {
+        return String.format("%02d-%02d-%04d", this.day, this.month, this.year);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        DateYMD dateYMD = (DateYMD) o;
+        return day == dateYMD.day && month == dateYMD.month && year == dateYMD.year;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(day, month, year);
+    }
+}