A sphere just fits inside a cube with edges 20 in. Long. What is the volume of the sphere? What is the volume of the cube? What is the volume of the space between the cube and sphere?

For the M1 angle, we can conclude the size of angle is 90°. Do the angle equation like this :

15x=90

x = 90/15

x = 6

Do the same thing in M2 :

Subtitute the x value to equation, then evaluate the value by using 90 because it's the same.

x+y=90

6+y=90

y=90-6

y=84

M3 value is same, 90°

9z=90

9z/9 = 90/9

z=10

Hope this helps