Answer:
base = 32 cm , height = 40 cm
Step-by-step explanation:
ratio of base : height = 4 : 5 = 4x : 5x ( x is a multiplier )
The area (A) of a triangle is calculated as
A = [tex]\frac{1}{2}[/tex] bh ( b is the base and h the height ) , then
A = [tex]\frac{1}{2}[/tex] × 4x × 5x = 2x × 5x = 10x²
given A = 640 , then
10x² = 640 ( divide both sides by 10 )
x² = 64 ( take square root of both sides )
x = [tex]\sqrt{64}[/tex] = 8
Then
base = 4x = 4 × 8 = 32 cm
height = 5x = 5 × 8 = 40 cm
