Question

The height of a wooden pole, h, is equal to 20 feet. A taut wire is stretched from a point on the ground to the top of the pole. The distance from the base of the pole to this point on the ground, b, is equal to 15 feet.
What is the length of the wire, l?
A. 625 feet
B. 20 feet
C. 13 feet
D. 25 feet

Answer 1

ANSWER

D. 25 feet

EXPLANATION

The height of the wall,h, the taut wire and the distance from the base of the pole to the point on the ground, formed a right triangle.

According to the Pythagoras Theorem, the sum of the length of the squares of the two shorter legs equals the square of the hypotenuse.

Let the hypotenuse ( the length of the ) taught wire be,l.

Then

${l}^{2} = {h}^{2} + {b}^{2}$

${l}^{2} = {20}^{2} + {15}^{2}$

${l}^{2} = 400 + 225$

${l}^{2} = 625$

$l= \sqrt{625} = 25ft$