Question

a triangle has a base that is 3 times longer than its height. it has a area of 486 sq cm. what is the base and height

Answer 1

B = 3h . . . . . . . .given by the problem statement
A = (1/2)bh . . . . formula for the area of a triangle

486 cm² = (1/2)*(3h)*h . . . substitute given information
(2/3)*486 cm² = h² . . . . . .multiply by 2/3
√324 cm = h . . . . . . . . . . . . . .take the square root

The height is 18 cm.
The base is 3*18 = 54 cm.