A wooden plank is leaning against an outside wall of a building. The bottom of the plank is 3 ft from the wall. Find each of the following values, and show all your work.
(A) Find the approximate length of the plank. Round to the nearest tenth of a foot. Given that the distance of the ground is 3ft. In order to get the length of the plank, we can use the this one.
cos 49 = ground / plank cos 49 = 3 / plank plank = cos 49 / 3 plank = 0.10 ft
(b) Find the height above the ground where the plank touches the wall. Round to the nearest tenth of a foot. The remaining angle is equal to angle = 180 - (90+49) angle = 41
Finding the height. tan 41 = height / ground tan 41 = height / 3 height = tan 41 / 3 height = 0.05 ft.
