Question

What is 12/15 = ab/20
(geometry converse of pythagorean theorem)

Answer 1

31

Explanation:

In circle S: XB and XD are tangents at B and D

then SB perpendicular to AX and SD perpendicular to XC

In triangle SDX: SD = 12 and SX =20 by using Pythagoras Theorem

XD = XB tangents to circle S from point X

XA = XC tangents to circle R from point X

then BA = DC = 15

then XC = XD + DC = 16 + 15 = 31