Question

If the circumference of a circle increases from 4π to 8π, then its area is
(a)halved
(b)doubled
(c)tripled
(d)quadrupled

Answer 1

Answer:

Its area is quadrupled.

Among the given options option (d) quadrupled is the correct answer.

Step-by-step explanation:

Given :  

Circumference of the circle increases from 4π to 8π.

Circumference of a circle = 2πr

Case 1 : When circumference = 4π

C = 4π  

2πr = 4π

2r = 4

r = 4/2

r = 2  

Radius = 2  

Area of a circle,A = πr²

A = 22/7 × 2²

A = (22/7 × 4) ……. ..(1)

Case 2 : When circumference = 8π

C = 8π  

2πr = 8π

2r = 8

r = 8/2

r = 4  

Radius = 4

Area of a circle,A = πr²

A = 22/7 × 4²

A = 22/7 × 16  

A = 4 (22/7 × 4) ……. ..(2)

From eq 1 and 2 , it is clear that area is quadrupled.

Hence, its area is quadrupled.

HOPE THIS ANSWER WILL HELP YOU….

Answer 2

hope this answer will help you .....!
(D) Quadrupled