If a circle has a 16in diameter what is the formula to find its area

The formula is Area = pi * Radius * Radius. Computing the answer gives you 64pi as the area for a circle with a 16in diameter

Step-by-step explanation:

Radius = diameter/2 = 16/2 = 8

Area = pi * radius * radius = pi * 8 * 8 = 64pi

idk

step-by-step explanation:

second option

step-by-step explanation:

the measures of a triangle equal 180. use that to find x.

2x+3x+4x=180

9x=180

9x/9=180/9

x=20

now you know x, you know angle a is 40°, angle b is 60°, angle c is 80°.

because angle a is 40°, the first option doesn't work.

because angle b is 60°, the second option does work.

when you add angle a and b, you get 100°. complementary means it equals 90°, so the third option doesn't work.

when you add angle a and c, you get 120°, which is not 100.