Which equation is the equation of a circle with a diameter of 20 cm and center at (-3, 6)?
a. (x-3)^2 + (y+6)^2 = 400
b. (x-3)^2 + (y+6)^2 = 100
c. (x+3)^2 + (y-6)^2 = 100
d. (x+3)^2 + (y-6)^2 = 400

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.