How do you calculate the area of a circle? area of a circle is equal to the diameterdiameter squaredradiusradius squared times diameterheightpiwidth.

Step-by-step explanation:

We need to find about how to calculate the area of a circle.

And match with the given choices. Where given choices are:

Area of a circle is equal to the diameterdiameter

squaredradiusradius squared times diameterheightpiwidth.

I'm not sure what exactly you have typed lol :)

But I can still answer that.

You just need to apply formula of the area of circle which is given by:

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.

80

step-by-step explanation: