Find the height of the central support of the seesaw and explain how to find this.
From the end of the see-saw to point R is 4 feet (1/2 of the total length, 8)
Now you have a right triangle with hypotenuse of 4
sin 25 = opp/hyp = h/4
sin25 = .42262 = h/ 4 h = 1.69 ft