Question

If you place a 37-foot ladder against the top of a 12-foot building, how many feet will the bottom of the ladder be from the bottom of the building?

Answer 1

The building will be making 90° with the ground/horizontal.

Then we can apply Pythagoras theorem.

(Base)² + (Height)² = (Hypotenuse)²

=> x² + (12 foot)² = (37 foot)²

=> x² = (37 foot)² - (12 foot)²

We can expand LHS using a² - b² = (a + b)(a - b)

=> x² = (37 + 12 foot)(37 - 12 foot)

=> x² = 49 * 25 foot²

=> x² = (7 * 5)² foot²

=> x = 7 * 5 foot

=> x = 35 foot.