Answer:
1. 8 + 4 = 12 x 6 = 72
2. 9 + 6 = 15 x 4 = 60
3. 11 + 8 = 19 x 6 = 114
4. 4 + 6 = 10 x 5 = 50
5. 7 + 3 = 10 x 8 = 80
6. 8 + 12 = 20 x 9 = 180
7. 5 + 10 = 15 x 8 = 120
8. 19 + 13 = 32 x 10 = 320
9. 3 + 6 = 9 x 2 = 18
Area of a trapezoid:
Base 1 + Base 2 times Height times a half (basically dividing by 2).