Geometry Word Problem

Question

You are making hand shadows on a wall using a flashlight. You hold your
hand 1 foot from the flashlight and 5 feet from the wall. Your hand is parallel
to the wall. If the measure from your thumb to ring finger is 6 inches, what
will be the distance between them in the shadow?

Answer 1

Draw and label a diagram.

Two overlapping similar triangles are formed.

Both have a vertex at the light source.

The smaller has a base (your hand) of 6 and an altitude of 1 (distance from light.

The larger has a base of x (the width of the shadow and an altitude of 6 (5 + 1).

The larger triangle is 6 times the size of the smaller.

Therefor the shadow is 6 times the size of the hand, 36 inches.