Answer: 120 cm²
Explanation:
Let's start by finding the area of one triangle
The formula for finding the area of a triangle is

Where
A is the area
h is the height (5 for this)
and b is the base (4 for this)
Let's sub in our values and solve.

Since there are 12 triangles in the shape we must multiply our area for one triangle by 12 to find the total area of the shape
12×10=120