Math Review Help

Question

School just started yesterday and I got a review sheet from my teacher. I completely forgot how to do this. Can anyone help me? Question: A 30ft cable extends from the floor of the lookout of a fire tower. The cable is anchored to the ground 18ft away from the base of the tower. What is the height of the floor of the lookout tower?
A) 48ft
B) 35ft
C) 24ft
D) 10ft

Answer 1

Draw a picture and you will see that there is a right triangle, with the tower being one leg, the distance from the tower to the cable anchor being the other leg, and the cable being the hypotenuse.  Use the Pythagorean Theorem:

 

a² + b² = c²

• a = 18 ft
• b = height of tower
• c = cable length = 30 ft

 

Solve for b.