Question 110

# A ladder just reaches a window that is 8 metres high above the ground on one side of the street. Keeping one end of the ladder at the same place, the ladder is moved to the other side of the street so as to reach a 12 metre high window. If the ladder is 13 metres long, what is the width of the street?

Solution

We can represent the given information in the diagram as follows:

The width of the street = BD = BC + CD

$$\Rightarrow$$ $$\sqrt{13^2 - 8^2}$$ + $$\sqrt{13^2 - 12^2}$$

$$\Rightarrow$$ $$10.24$$m + $$5$$m = 15.2 m. Hence, option C is the correct answer.