If the diameter of a circle is 20cm, what is the area?

Question

can someone please show me how to do ir or have a web page that shows me how to get the answer because people are giving me different formulas

Answer 1

A = π r² ; r = d/2

A = π (d/2)² = π d²/4

Plug in your number of 20

A = π (20)²/4 = π 400/4 = 100π

The formal answer is:  100π cm²

Which is approximately 314.2 cm²

Answer 2

197.4cm^2

Answer 3

A = (pi)(r^2)

A = (pi)(10^2)

A = (pi)(100)

A = 314.159 = Final Answer