(See the imagine for reference)
Let’s solve where they have a triangle, so the height is 9 cm, the base is 3 cm:
1/2 • 9 • 3 = 13.5
Since there’s 2 triangles we do:
13.5(2) = 27
Now the rectangle in the middle, where the height is 9cm and the base is 12cm:
12 • 9 = 108
Add up the areas:
108 + 27 = 135
Let’s solve where they have a triangle, so the height is 9 cm, the base is 3 cm:
1/2 • 9 • 3 = 13.5
Since there’s 2 triangles we do:
13.5(2) = 27
Now the rectangle in the middle, where the height is 9cm and the base is 12cm:
12 • 9 = 108
Add up the areas:
108 + 27 = 135