Question

A rope 29 ft long rope is tied to the top of a flag pole. The rope is staked to the ground 21 ft away from the base of the pole. How tall is the flag pole?

Answer 1

Answer: 20 ft

Step-by-step explanation:

Given: The length of rope tied to the top of a flag pole=29 ft

The distance between base of the pole and the point on ground where the rope is stacked= 21 ft

Let x be the height of flagpole.

Now, we can see the figure that the given situation represents a right triangle

Where longest side= 29

By Pythagoras theorem of right triangle, the square of the longest side is equal to the sum of the squares of the other two sides.

$29^2=21^2+x^2\\\Rightarrow\ x^2=29^2-21^2\\\Rightarrow\ x=841-441\\\Rightarrow\ x=400\\\Rightarrow\ x=\sqrt{400}\\\Rightarrow\ x=20$

Hence, the height of flagpole = 20 ft.

Answer 2

It's like A2+B2=C2 so:
A2+B2=C2
A2+ 21(squared)=29(squared)
A2=441=841
A2=400
A=√(400)
A=20