What is the reason behind this SAT Math Question?

Sikorsky
Thu, 01 Aug 2013 22:24:13 +0000

The simple answer is that when the sides are perpendicular, the height of the triangle is greatest.

If you know a little trig, and you think of the area of the triangle as (1/2)bc*sin(A), b and c are fixed, and sin(A) is at its greatest when angle A measures 90°.