Answer:
First we will find the surface area of the right triangle.
area of the right triangle=1/2*base*height.
now multiply it by 2 then we will get the S.A of both the right triangles.
Now, the other seems to be a rectangle,so find its area. And also the unseen side is a rectangle so find its area also .
And. now at the last. plus. the area of all the sides. you will get your answer. understand buddy.