We are given some information about a ladder leaning on a building. We know that the base of the ladder is 10 feet away from the building and that the top of the ladder reaches 15 feet on the side of the building.
Note that the ladder, the side of the building, and the ground form a right triangle. The length of the ladder is the hypotenuse of this triangle. To evaluate it, we can use the Pythagorean Theorem.
The Pythagorean Theorem
If a triangle is a right triangle, then the square of the length of the hypotenuse is equal to the sum of the squares of the lengths of the legs.
c^2=a^2+b^2
In our case, the lengths of the legs are 10 and 15 feet. We can substitute these values into the formula and solve it for c.
Since a negative length of the ladder does not make sense, we only need to consider the positive solution. Therefore, the given ladder is about 18 feet long.
