Answer:
2100 cm
Explanation:
Since a=20 cm, b=25 cm, c=28 cm, we can calculate the area by calculating the separate squares and triangles and then adding them together.
To find the square's areas we can use the equation A=LxW
A=20x25
A=500
Since there are two identical squares add them together.
500+500=1000
Next, calculate the area for the bottom square.
A=25x28
A=700
And then add the two surface areas together.
1000+700=1700
Finally, calculate the area of the two triangles by adding them together to create one square, and then calculating their area.
A=20x20
A=400
Since we know the final surface area we can add them all together to get our answer of 2100 cm.
400+1700=2100