1. The problem statement, all variables and given/known data A rectangular windshield is to be assembled by installing a glass plate on a 3 ft by 1 ft frame at 60°C. The glass plate is cut at 68°F in such a way that its length is three times its width. The linear expansivity of glass is 5 x 10-6 /C°. (a) What area of the glass plate at 68°F will exactly fit the frame at 60°C? (b) What length of the glass plate at 68°F will exactly fit the frame at 60°C? (c) What width of the glass plate at 68°F will exactly fit the frame at 60°C? 2. Relevant equations Af = Ao(1+2αΔT) Where: Af = Final Area Ao = Initial Area α = coefficient of expansion ΔT = Change in Temperature L = 3W Where: L = Length W = Width 3. The attempt at a solution From what I understand, I am suppose to find the initial area of the glass plate to be fitted in the frame. First, manipulate the area expansion formula to find Ao: Ao = Af / (1+2αΔT) Substituting the values, I will arrive with: Ao = 2.9988 ft2 → (a) Next, find the length of the initial area by using L=3W, where: Ao = L*W Ao = L*L/3 L = √(3*Ao) Substituting the values, I will arrive with: L = 2.9944 ft → (b) Finally, using L=3W to find the width: L=3W W=L/3 W=0.9998 ft → (c) Is this the right answer? The initial values seems too close to the final.