Question

use a 15 cm long string and join its ends. place it on cm squared paper to make a square ,a circle, a triangle, and a rectangle. find the area of each shape .which shape has the largest area ?which shape ha a smallest area?​

Answer 1

The shapes with largest area and shape with smallest area are circle and triangle.

Step-by-step explanation:

Length of the string = 15 cm

Thus, perimeter = 15 cm

Square:

A square has four sides.

One side:

a = 15/4 = 3.75 cm

Area:

As = a² = (3.75)² = 14.06 cm²

Circle:

Circumference:

C = 2πR

15 = 2πR

∴ R = 15/2π

Area:

Ac = πR² = π(15/2π)²

Ac = 17.9 cm²

Triangle:

A triangle has three sides. Since, many triangles are formed with this measurement. Equilateral triangle is considered.

Side:

a = 15/3 = 5 cm

Area:

At = (√3 /4) a²

At = (√3 /4)5² = 10.8 cm²

Rectangle:

Since, many rectangles can be formed with given string. One of the value is mentioned below.

When l = 7 cm and w = 0.5 cm, the area is:

Ar = 7 × 0.5 = 3.5 cm²

Conclusion:

Ac > As > At > Ar

Answer 2

Answer is also make triangle .square.rectangle and circle