3a. Area = 2 (5×7 + 5×3 + 7×3)
3b. Area = 2 (6×6 + 6×5 + 6×5)
3c. Area = 2 (6.5×10 + 6.5×3 + 3×10)
4a. Area = 2(1/2 × 4 × 6) + 2(7×5) + 7×6
4b. Area = 2(1/2 × 6 × 6) + 2(10×8.5) + 10×6
4c. Area = 2(1/2 × 10.2 × 3.6) + 15×8.3 + 15×4.5 + 10.2×15
