Solution: 137
Explanation: A triangle's area is defined by the formula; height × 1/2 base. BUT it has always been easier for me to do height × base then divide by 2.
3 × 6 = 18
18 ÷ 2 = 9
or if you prefer traditional;
3 ÷ 2 = 1.5
1.5 × 6 = 9
Both equal 9.
Now you move onto the rectangle.
Formula: height × length
16 × 8
= 128
Add the two shapes' areas together.
128 + 9 = 137