It's just Base * Height / 2
A = 1/2 * B * h in formula form.
The base in this case deserves some comments.
- The height always meets the base at right angles.
- The height starts at one of the angle vertex's and ends at the base or the base extended. In this case the base is the base extended.
- The base extended is the dashed line.
- The base extended is not part of the measured length of the base.
Area = 1/2 base * height
base = 7.9
height = 6.3
Area = 1/2 * 7.9 * 6.3
Area = 24.885 in^2
If you are supposed to round then it would be 24.9 to 3 places.