How do you find the surface area of this figure?

SA=158cm²

Step-by-step explanation:

To find surface area, you find the area for all the surfaces and add them together. Let's start with the red rectangular prism first.

The top has measurements of 5 and 2. The area of that is 10.

The bottom is the same so it's area is also 10 but we don't want to add it since it's not on the surface.

The side facing us has measurements of 4 and 2, the area is 8.

The side opposite to this is the same so it's area is also 8

Now the right face of this shape is 4 and 4 so 16.

The left face will have the same area. It'll also be 16.

The surface area of the red shape is 10+8+8+16+16= 58

Now the orange shape.

The side facing us is 5 and 3 so area=15

The side opposite to this will have the same area.= 15

The right face is also 5 and 3 so 5x3=15

The opposite face to this will also have an area of 15

Now the top face, it's 5 and 5 = 25. We have to subtract the area covered by the red shape. So 25 - 10 = 15

The bottom face's area will be 25.

The surface area of this shape will be : 15+15+15+15+25=100

Now add the areas of both shapes

58+100 = 158

SA=158cm²

Hope this helps :)

A u B = { 3, 4, 5, 7, 8, 9, 12 }

Step-by-step explanation:

The union of sets u is the set of elements in set A, or set B, or both

Thus

A u B = { 3, 4, 5, 7, 8, 9, 12 }