first find the area of the square, the formula is base times height area of the square=25
then find the area of the triangles, the formula is 1/2bh,the area of the triangle is 20, there r 4 identical triangles so multiply 20 by four the find the surface area of all of the triangles= 80 to find the the total surface area u add the area of the triangles to the area of the square=105
The answer is C.105 centimeters squared