Question

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

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

Answer 1

The correct option is C $15$m

Consider the two trees as perpendiculars on the ground forming a right triangle, where the distance between their bases is the base $\left(B\right)$, the distance between their tops is the Hypotenuse $\left(H\right)$ and difference between their lengths is the perpendicular $\left(P\right)$.
Hypotenuse, $H=17$ m
Perpendicular, $P=$ distance between their lengths $=28-20=8$ m
Thus, By Pythagoras Theorem,
$H^2=P^2+B^2$
${17}^2=8^2+B^2$
$B^2=289-64$
$B=15m$.