A 21-foot ladder is leaning against a building. The base of the ladder is 7 feet from the base of the building. To the nearest degree, what is the measure of the angle that the ladder makes with the ground? (Hint: Sketch the problem before solving.)
+23247 You have a right triangle and you want to find the size of the angle that is formed by the 7' length and the 21' length. The 7' length is adjacent to the angle while the 21' length is the hypotenuse of the triangle.
Since you have the adjacent side and the hypotenuse, use the cosine because cos = adj/hyp
cos X = 7/21 ---> X = invCos (7/21)
