Question

The distance between the top of two trees 20 m and 28 m high is 17 m. Find the horizontal distance between the trees.

• A. 11 m
• B. 31 m
• C. 15 m
• D. 9 m

Answer 1

The correct option is C

15 m

Let AB and CD be two trees such that AB = 20 m, CD = 28 m & BD = 17 m

Draw BE perpendicular to CD. Then, AB = EC

ED = CD - EC = CD - AB [Since AB = EC]

ED = 28 m - 20 m = 8 m.

Using Pythagoras Theorem,

∴ BE = $\sqrt{{BD}^2-{ED}^2}$ = $\sqrt{{\left(17\right)}^2-8^2}$

= $\sqrt{225}$ = 15 m.

∴ AC = BE = 15 m.