Answer:
25.5 u²
Explanation:
Find the area of the rectangle, then the area of the triangle. To get the final area, add them together.
Rectangle: 3 x 5 = 15
Triangle: 3 x 7 ÷ 2 = 10.5
Total: 15 + 10.5 = 25.5 u² (you put it in units since you don't know the measure, e.g. cm, m, km...)