Answer:
1,736 square units
Step-by-step explanation:
To find the surface area, you must first find the area of all the faces, then add them all together. For this figure, you must find the area of two triangles, and three different rectangles.
Starting with the triangles, you can find the area using the equation: a=1/2bh. This gets 84 as the area of one triangle. Because you have two, you can multiply this area by two in order to get the area of both triangles. That value is 168.
Now, find the area of the bottom rectangle. Its dimensions are 24x28, and you can find the area of any rectangle by multiplying its base by its height. This area is 672.
The back rectangle's dimensions are 28x7, which equals 196.
The top rectangle is most difficult, as you must use the pythagorean theorem to find one of its side lengths: a^2 + b^2 = c^2. Its dimensions are 25x28, which equals 700.
Now add all those areas together to get the total surface area, or 1,736.
