In right triangle ABC, AC is the hypotenuse. If AC is 20 and AB + BC = 50, what is the area of the triangle ABC?	Choose the correct choice.
A) 225 B) 525 C) 25√2 D) 200 E) 200√2
Square AB + BC = 50:   (AB)^2 + 2*AB*BC + (BC)^2 = 2500. Since (AC)^2 = (AB)^2 + (BC)^2 = 20^2 = 400, then (AB)^2 + 2*AB*BC + (BC)^2 = 400 + 2*AB*BC = 2500.   400 + 2*AB*BC = 2500.   AB*BC = 1050.   The area = 1/2*AB*BC = 525.   Answer: 525.
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In right triangle ABC, AC is the hypotenuse. If AC is 20 and AB + BC = 50, what is the area of the triangle ABC?