What is the are of an equilateral triangle of side 20 cm?
Options:
(A) 645
(B) 649
(C) 644
(D) 643
(E) 1003 Stream of consciousness:
Area of an equilateral triangle = 3/4 S2
If S = 20, Area of triangle = 3/4 * 20 * 20 = 1003 cm2;
Thus, the answer is (E).