A 23 ft ladder is placed against a college classroom building at a point 20 ft above the ground. What is the distance from the base of the ladder to the building

Respuesta :

The ladder forms the hypotenuse of a right triangle. Solve for a 

a^2 + b^2 = c^2 
a^2 + 9^2 = 18^2 
a^2 + 81 = 324 
a^2 = 243 
a = 15.589 = 15.6 feet