Answer: 75
Explanation:
Separate the parallelogram into two identical triangles (0.5 length by 10 height) and a rectangle (8 length by 10 height).
Work out the area of the rectangle - 8 * 10 = 80
Work out the area of the triangle - 0.5 * 10 = 5 (you don't need to halve it as you have two triangles)
Work out the area of the parallelogram - 80 + 5 = 85
Work out the area of the purple rectangle? (it says triangle in your description but I'm pretty sure that's not a triangle) - 5 * 2 = 10
Work out final area of the parallelogram - 85 - 10 = 75
I'm not sure if this is right but either way I hope you get your answer :)