Question

Olivia measures the heights of two trees and the lengths of their shadows. She notices that the height of each tree and the length of its shadow are directly proportional. One of the trees has a height of 15 m and a 10 m long shadow. The other tree has a 14.4 m long shadow. Calculate its height, in metres (m). Give any decimal answers to 1 d.p. 15 m 10 m ? m 14.4 m​

Answer 1

Explanation:

directly proportional means

y = kx

with k being a constant factor for all values of x.

we get k by using the given data point (10, 15).

15 = k×10

k = 15/10 = 1.5

so, now for the other tree we know k and x and calculate y

y = 1.5×14.4 = 21.6 m

it is 21.6 m tall (its height is 21.6 m).