What is the are of an equilateral triangle of side 16 cm?
Options:
(A) 663 cm2
(B) 743 cm2
(C) 643 cm2
(D) 645 cm2
(E) 143 cm2 Hmmm, my stream of consciousness:
Area of an equilateral triangle = 3/4 S2
If S = 16, Area of triangle = 3/4 * 16 * 16 = 643 cm2; So, the answer is (D).