Question

Nachelle is 1.45 meters tall. At 11 a.m., she measures the length of a tree's shadow to be 23.05 meters. She stands 18.9 meters away from the tree, so that the tip of her shadow meets the tip of the tree's shadow. Find the height of the tree to the nearest hundredth of a meter.

Answer 1

Explanation:

this creates 2 similar triangles.

that means all angles are the same. and all the side lengths of one triangle correlate to the corresponding side lengths of the other triangle by the same multiplication factor.

her shadow is 23.05 - 18.9 = 4.15 m long.

the factor between the shadow lengths is then

4.15 × f = 23.05

f = 23.05 / 4.15 = 5.554216867...

the same factor now applies to the relation of the heights :

1.45 × 5.554216867... = 8.053614458... m

rounded the tree is 8.05 m tall.