Hello!
To find the surface area you can divide the prism into the 2D shapes it is made of
First list out all the shapes
2 triangles with bases of 18 and heights of 15.6
3 rectangles with side lengths of 20 and 18
First find the area of the triangles
The equation to find the area of a triangle is
A is area
h is height
b is base
Put in the values you know
Solve
A = 140.4
The triangles have an area of 140.4 units
Next we find the area of a the rectangles
To do this we multiply the sides
18 * 20 = 360
The rectangles have areas of 360 units
Now we add all the areas
There are 2 triangles and 3 rectangles
140.4 + 140.4 + 360 + 360 + 360 = 1360.8
The answer is B) 1360.8cm squared
Hope this helps!
To find the surface area you can divide the prism into the 2D shapes it is made of
First list out all the shapes
2 triangles with bases of 18 and heights of 15.6
3 rectangles with side lengths of 20 and 18
First find the area of the triangles
The equation to find the area of a triangle is
A is area
h is height
b is base
Put in the values you know
Solve
A = 140.4
The triangles have an area of 140.4 units
Next we find the area of a the rectangles
To do this we multiply the sides
18 * 20 = 360
The rectangles have areas of 360 units
Now we add all the areas
There are 2 triangles and 3 rectangles
140.4 + 140.4 + 360 + 360 + 360 = 1360.8
The answer is B) 1360.8cm squared
Hope this helps!