Area and Perimeter Practice Test 4

Question : 31 of 40

Marks: +1, -0

If the radius of a circle is decreased by 50%, its area will decrease by:

Solution:

Area of circle =

πr^2

Area of new circle =

π . (r/2)^2

{πr^2}/4

Change in Area =

πr^2- {πr^2}/4

3/4 πr^2

Required percentage =

{3/4 πr^2}/{πr^2} × 100

= 75 %

Go to Question:

Prev Question

Next Question