In triangle ABC, angle B = 90 degrees. Point X is on line AC such that angle BXA = 90 degrees, AX = 15, and AB = 25. What is BX?
Using Pythagoras theorem in \(\triangle ABX\) gives \(AX^2 + BX^2 = AB^2\), substituting AX = 15 and AB = 25 gives
\(15^2 + BX^2 = 25^2\\ BX^2 = 400\\ BX = 20\)
+109 
