Find the area of the shaded region .

Calculate area of the white region inside circle.

Area of the two white triangles in top left and bottom right:

Area of the two white quarter circles in the bottom left and top right:

Total area of unshaded white region inside circle:

Area of entire circle including the white and shaded regions

Area of shaded region is area of entire circle - area of unshaded white region

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.