Answer:
The correct are is 5.5 cm².
Explanation:
First of all, Carlos calciulated the are of the rectangle correctly, only the are unit is wrong, it should be 3 cm².
He made a mistake calculating the area of a the triangle: The area of a triangle can be calculated by multiplying the base by the height by
.
(Comment if you want a deeper explanation on where this comes from)
He mistakenly takes 4 cm for the height, but if you look carefully the height of the triangle in this case is 4 cm - 1.5 cm = 2.5 cm.
That gives
for the area of the triangle.
Adding those two together gets you a total area of 5.5 cm².