Hey there! I’m happy to help!
The surface area is basically the area of the surface of the shape. So, if you have a cube, it’s the area of all of the surface of the cube, not anything inside.
We see that we have a net of this square pyramid. If we fold it up, the square and four triangles will make up the surface of the 3D shape we see. So, we need to find the area of all of these shapes.
SQUARE
To find the area of a square, you multiply one of the sides by itself (all the sides are the same)
10(10)=100
TRIANGLES
To find the area of a triangle, you take the base and multiply the height and then divide it by two.
10(12)=120
120/2=60
Since we have four triangles, we multiply it by four.
60(4)=240
Finally, we add this all up.
240+100=340
Therefore, the answer is 340 square inches.
I hope that this helps! Have a wonderful day!