12. The circumference of a quarter is about 76 mm. What is

the area? Round to the nearest tenth.

Answer: A = 460 mm2

Step-by-step explanation:

Hi, since the circumference formula is:

C = 2 π r

Where r is the radius, we can solve the formula for the radius replacing with the value given:

76 = 2 π r

76 / (2 π) = r

r = 12.1 mm

Now, we have to apply the formula for the area of a circle.

A = π r^2

A = π (12.1) ^2

A = 459.96 mm2 = 460 mm2 (rounded to the nearest tenth, since. 9 is higher than. 5)

Feel free to ask for more if needed or if you did not understand something.