Question

Find the area of a circle with a radius of 5 feet. Round your answer to the nearest tenth. Find the area of a circle with a diameter of 56 millimeters. Round your answer to the nearest hundredth.

Answer 1

Case 1 :

Radius, r = 5 feet.

Area,

$A=\pi r^2\\\\A = 3.14\times 5^2\ feet^2\\\\A = 78.5\ feet^2$

Case 2 :

Diameter, d = 56 mm.

So, radius, r = d/2 = 28 mm.

Area,

$A = 3.14\times 28^2\ mm^2\\\\A = 2461.76\ mm^2$

Hence, this is the required solution.