1. It is a built different (lol) triangle. So, you want to multiply 8.3x4.1 to get 34.03 and divide that by 2 (A=L*W/2) to get 17.015in.
2. Another triangle, so multiply 13*9 to get 117 and divide that by 2 to get 58.5 yds.
3. This is not a triangle so just A=L*W*H. So, multiply 14.8*17.3*8.1 to get 2073.92 yds.
4. This is a triangle and we need to find the height of the triangle. So, we need to divide 26.27 by 3.7 to get 7.1 as the height.
Have a great day!