5m ladder leans against a house it is 3 m from the base of the wall how high does that ladder reach?

well, a^2 + b^2 = c^2

c is hypotenuse and a and b are either the adjacent or the opposite.

a^2 + 3^2 =5^2

a^2= 25 -9


a = 4

therefore the ladder reaches 4 meters high.