Two spherical balls lie on the ground touching. If one of the balls has a radius of 6 cm, and the point of contact is 10 cm above the ground, what is the radius of the other ball (in centimeters)?	Choose one.
A) 12 B) 16 C) 20 D) 24 E) 30
A straight line will join the two centers and the point of contact, thus making similar triangles.   4/6 = (r-10)/r   4r = 6r - 60   r = 30   The answer is 30.
<result>E</result>
Two spherical balls lie on the ground touching. If one of the balls has a radius of 6 cm, and the point of contact is 10 cm above the ground, what is the radius of the other ball (in centimeters)?