The area of $\triangle ABC$ is 6 square centimeters. $\overline{AB}\|\overline{DE}$. $BD=4BC$. What is the number of square centimeters in the area of $\triangle CDE$?
Similar triangles....CD is 3 times bigger than BC so the larger triangle is dilated by factor of 3 ...each side is 3 times bigger than the smaller
area of larger = 3 * 3 * 6 = 54 cm2
