A25-foot ladder leans against a wall. the base of the ladder is 15 feet from the bottom of the wall. how far up the wall does the top of the ladder reach?

20 feet.

Step-by-step explanation:

Observe the right triangle attached.

You need to find the value of "x".

Then, you can use the Pythagorean Theorem:

Where "a" is the hypotenuse of the triangle, and "b" and "c" are the legs.

 In this case, you can identify that:

Substitute these values into  :

Now, you need to solve for x to find how far up the wall the top of the ladder reaches. Then you get:

ANSWER

20ft

EXPLANATION

The ladder, the wall and the ground formed a right triangle.

Let how far up the wall does the top of the ladder reached be x units.

The 25ft ladder is the hypotenuse.

The shorter legs are, 15ft and x ft

Then from Pythagoras Theorem,

Therefore the ladder is 20 ft up the wall.