add task solution

src/figuresClasses.ts

@@ -1,11 +1,81 @@
-export interface Figure {}
+export interface Figure {
+  shape: 'triangle' | 'circle' | 'rectangle';
+  color: 'red' | 'green' | 'blue';
+  getArea(): number;
+}
+
+type Color = 'red' | 'green' | 'blue';
+
+export class Triangle implements Figure {
+  shape: 'triangle' = 'triangle';
+
+  constructor(
+    public color: Color,
+    public a: number,
+    public b: number,
+    public c: number,
+  ) {
+    if (a <= 0 || b <= 0 || c <= 0) {
+      throw new Error('All triangle sides must be greater than 0');
+    }
+
+    const max = Math.max(a, b, c);
+    const sum = a + b + c;
+
+    if (max >= sum - max) {
+      throw new Error(
+        'Triangle sides cannot form a valid triangle: longest side must be less than sum of other two sides',
+      );
+    }
+  }
+
+  getArea(): number {
+    const p = (this.a + this.b + this.c) / 2;
+    const area = Math.sqrt(p * (p - this.a) * (p - this.b) * (p - this.c));
+
+    return Math.floor(area * 100) / 100;
+  }
+}
+
+export class Circle implements Figure {
+  shape: 'circle' = 'circle';
+
+  constructor(
+    public color: Color,
+    public radius: number,
+  ) {
+    if (radius <= 0) {
+      throw new Error('Circle radius must be greater than 0');
+    }
+  }
+
+  getArea(): number {
+    const s = Math.PI * this.radius ** 2;
 
-export class Triangle implements Figure {}
+    return Math.floor(s * 100) / 100;
+  }
+}
+
+export class Rectangle implements Figure {
+  shape: 'rectangle' = 'rectangle';
 
-export class Circle implements Figure {}
+  constructor(
+    public color: Color,
+    public width: number,
+    public height: number,
+  ) {
+    if (width <= 0 || height <= 0) {
+      throw new Error('Rectangle width and height must be greater than 0');
+    }
+  }
 
-export class Rectangle implements Figure {}
+  getArea(): number {
+    const s = this.width * this.height;
+
+    return Math.floor(s * 100) / 100;
+  }
+}
 
-export function getInfo(figure): string {
-  return typeof figure;
+export function getInfo(figure: Figure): string {
+  return `A ${figure.color} ${figure.shape} - ${figure.getArea()}`;
 }