This forms a right triangle.
The 25-ft ladder is the hypotenuse of the right triangle.
Part of the wall is a leg.
Part of the ground is a leg.
For the angle where the ladder meets the ground, the
ground is the adjacent leg. The ladder is the hypotenuse.
Call the angle between the ladder and the ground angle A.
The trig ratio that relates the adjacent leg and the hypotenuse is the cosine.
[tex] \cos A = \dfrac{adj}{hyp} [/tex]
[tex] \cos A = \dfrac{7}{25} [/tex]
[tex] \cos A = 0.28 [/tex]
[tex] A = \cos^{-1} 0.28 = 73.7397... [/tex]
Answer: 74 degrees.
