Hi there!
We can find the area of a triangle with the formula:
[tex]area = 0.5 \times base \times height[/tex]
Filling in this formula gives us the following answers.
Triangle 1
[tex]area = 0.5 \times 5 \times 8 = 20[/tex]
Triangle 2
[tex]area = 0.5 \times 7 \times 9 = 31.5[/tex]
Triangle 3
[tex]area = 0.5 \times 16 \times 12 = 96[/tex]