A circle has the area 126 . To the nearest tenth of a centimeter, find the length of its diameter.
A)6.3 cm
B)12.7 cm
C)19.0 cm
D)None of These

Question

A circle has the area 126  . To the nearest tenth of a centimeter, find the length of its diameter.
A)6.3 cm 
B)12.7 cm 
C)19.0 cm 
D)None of These

Quizplus · Accepted Answer

The formula for the area of a circle is A=πr² where r is the radius of the circle. To find the diameter, we need to find the radius first. 
A=πr² 
126.11=πr² 
r²=40 
r=√40=2√10 
The diameter is twice the radius, so 
d=2r=2(2√10)=4√10≈12.7 cm 
Therefore, the answer is B, 12.7 cm to the nearest tenth of a centimeter.

A Circle Has the Area 126