If the radius of a circle decreased by 50% its area is decreased by:
If the radius of a circle decreased by 50% its area is decreased by:
Answer/Solution
75
Steps/Work
Original area = πr(power)2
New area = π(r/2)(power)2 = (πr(power)2)/4
Reduction in area = [(πr(power)2 - (πr(power)2)/4]2 = (3πr(power)2)/4
Reduction percent = ((3πr(power)2)/4 × 1/(πr(power)2 × 100) % = 75%
Answer is A.
New area = π(r/2)(power)2 = (πr(power)2)/4
Reduction in area = [(πr(power)2 - (πr(power)2)/4]2 = (3πr(power)2)/4
Reduction percent = ((3πr(power)2)/4 × 1/(πr(power)2 × 100) % = 75%
Answer is A.