Question

Find the formula for the area A and the perimeter P of the shape shown find the area and perimeter when R is 5 cm find R when A is 100cm2 find r when P is 50cm find the value of r that makes A = p numerically

Answer 1

Answer:

1)Area; A = ¼πr²

Perimeter; P = πr/2 + 2r

2)A = 19.63 cm²

P = 17.85 cm

3) r = 8.885 cm

4) r = 14 cm

Step-by-step explanation:

This is a quadrant of a circle. Thus;

Area of a circle is πr². A quadrant is a quarter of a circle. Thus;

Formula for Quadrant Area is; A = ¼πr²

A) Perimeter of a circle is 2πr. Thus, perimeter of a quadrant is a quarter of the full circle perimeter.

Formula for the quadrant perimeter in the image given is;

P = 2πr/4 + 2r

P = πr/2 + 2r

B) When r is 5 cm;

A = ¼π(5)²

A = 19.63 cm²

P = π(5)/2 + 2(5)

P = 17.85 cm

C) when A is 100cm²:

¼πr² = 100

r² = 100 × 4/π

r² = 78.9358

r = √78.9358

r = 8.885 cm

D) when P = 50 cm.

50 = πr/2 + 2r

50 = (½π + 2)r

r = 50/(½π + 2)

r = 14 cm