What is the area of a semicircle with a diameter of 21.5

Area of a circle = PI x R^2

r = 1/2 diameter

r = 21.5/2

r = 10.75

Area of circle = 3.14 x 10.75^2 = 3.14 x 115.5625 = 362.86625 square units.

A semicircle is half a circle:

Area of semicircle = 362.86625 / 2 = 181.433125 square units (round the answer as needed).

i think it is c, not positive though

step-by-step explanation:

6mm^3 or .6cm^3

      216

      /   \

  36     6

  /   \     /

6     6   6

factor trees are nice.