Question

1. a man whose height is 2.1 m casts a shadow that is 3.2 m in length. what is the approximate height of a building that casts a shadow of 11.5 m? 2.1 m 3.2 m 11.5 m 10.4 m 7.5 m 17.5 m 9.6 m

Explanation:

Step1: Set up proportion

Since the ratios of height to shadow - length are equal, we have $\frac{2.1}{3.2}=\frac{h}{11.5}$, where $h$ is the height of the building.

Step2: Solve for $h$

Cross - multiply to get $3.2h = 2.1\times11.5$. Then $h=\frac{2.1\times11.5}{3.2}$.
Calculate $2.1\times11.5 = 24.15$, and $h=\frac{24.15}{3.2}=7.546875\approx7.5$ m.

Answer:

7.5 m