How do you find the formula of a half circle?

Full circle

Circumference = 2*pi * r

Circumference = pi * d

Area = pi r * r = pi * r^2

Area = pi d^2 / 4

Half circle

Circumference = pi * r

Circumference = pi * r / 2

Area = pi r^2 / 2

Area = pi d^2/8

The answer depends on what you are looking for and what you are given. But those are the only common formulas I can think of at the moment.

Ok don't report me but this answer is a blank because I want the other person to have brainliest NP