If the 3 sides of a triangle have lengths 9m, 12m, and 15m, what is the area of this triangle?

Answer 1

that is a 3,4,5 right triangle (25 = 9+16)
therefore if we take 4 as the base, 3 is the altitude
(1/2) b h = (1/2)(4)(3) = 6

Answer 2

therefore since the scale ration is 4/1, the ratio of areas is 16 to 1
16* 6 = 96

Answer 3

Whoops, sorry, 3/1
9*6 = 54

Answer 4

or just brute force do
(1/2)(12)(9) = 6*9 = 54