Answer: The height of the building = 14.5 feet.
Step-by-step explanation:
Given: Length of ladder = 15 feet
Distance of base of ladder from building = 4 feet
Since building is standing vertical on ground making right angle.
So with ladder a right triangle is formed , where base = 4 feet , Hypotenuse = 15 feet [Hypotenuse is side opposite to right angle]
According to the Pythagoras theorem ,
Hypotenuse² = Perpendicular² + Base²
⇒ (15)² = Perpendicular² + (4)²
⇒ 225 = Perpendicular² +16
⇒ Perpendicular² = 225 -16
⇒ Perpendicular² = 209
⇒ Perpendicular = √209 = 14.4568322948 ≈ 14.5 feet
Hence, the height of the building = 14.5 feet.