EXAMPLE: Solution. Let 0 be the viewing angle and let & = o + 8 as shown below. painting 10 ft tall viewing angle Oft eye level 5 ft 4 ft ft We observe that fan or = = and fan B = Using the Tangent Sum Identity, we have tan or + tan B tan 0 = tan (a + 8) = 1 - tan a tanB + 1 - 20 9 Using the calculator, the viewing angle is 0 = tan 20 9 = 65.8.1. A student is viewing a painting in a museum (see illustration below). Standing 6 ft from the painting, the eye level of the student is 5 it above the ground. If the painting is 2 ft tall and its base is 4 ft above the ground, find the viewing angle subtended by the painting at the eyes of the student. (There is an example attached below to solve this problem). viewing ange 2 ft eye level 4 ft