Answer:
Let's find the area of 1 triangle (this may not be the formula but I'm doing it in a more easier way).
20(base) x 10.5(height) = 210
210 divided by 2 ( x 1/2) = 105
Since there are 4 sides we must multiply the area of 1 triangle four times! Since there are 4 sides of triangles.
105 x 4 = 420
Oh and I almost forgot! We need to find the area of the square below!
20 x 20 = 400!
Now we add both areas of all the triangles and the area of the bottom square:
420 + 400 = 820 in2 is your answer. (we use the unit 2 since we are finding areas and adding them up)
Formula of a triangle:
BH x 1/2
B(base) x H(height) x 1/2 (basically just dividing by 2)
