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 8 cm above the ground, what is the radius of the other ball?  Select.
A) 12 cm	B) 16 cm	C) 18 cm	D) 20 cm	E) none of the these
similar triangle properties..   2/r+6 = 6/r-6   giving r = 12.   12 cmnswer: 12 cm
<result>A</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 8 cm above the ground, what is the radius of the other ball?