What height on the wall will a 15 foot ladder reach if it is placed 3.5 feet from the base of the wall...???

Answer:
14.6 feet
Step-by-step explanation:
Let the height of the ladder be the hypotenuse, the distance from the wall be the base and the height till the ladder reaches be the perpendicular.
Using Pythogoras theorem,
H^2 = p^2+b^2
p^2 = H^2-b^2
p = under root(H^2-b^2)
p = under root(225 - 12.25)
p = 14.6 feet