A photograph has a length 2 inches greater than its width. Its frame has a 2-inch border and a rectangular area of 120 square inches. What is the width of the photograph?
Solution to yesterday’s problem:
By supplementary angles, we know that angle DBC is 40°. Then, because angles in a triangle add up to 180°, we can say that . We are also given that angle B is 80 degrees more than angle D, so we can represent angle B as . Then we have . Solving this equation,
We conclude that angle D = 30°, angle B = 80°, and angle DBC = 40°. This checks out because the sum of the angles is 180°.