# Find the Surface Area pyramid (15)(8)(20)

h=15l=20w=8
The surface area of a pyramid is equal to the sum of the areas of each side of the pyramid. The base of the pyramid has area lw, and sl and sw represent the slant height on the length and slant height on the width.
(length)⋅(width)+(width)⋅sl+(length)⋅sw
Substitute the values of the length l=20, the width w=8, and the height h=15 into the formula for surface area of a pyramid.
20⋅8+8⋅(202)2+(15)2+20⋅(82)2+(15)2
Simplify each term.
Multiply 20 by 8.
160+8⋅(202)2+(15)2+20⋅(82)2+(15)2
Divide 20 by 2.
160+8⋅102+(15)2+20⋅(82)2+(15)2
Raise 10 to the power of 2.
160+8⋅100+(15)2+20⋅(82)2+(15)2
Raise 15 to the power of 2.
160+8⋅100+225+20⋅(82)2+(15)2
160+8⋅325+20⋅(82)2+(15)2
Rewrite 325 as 52⋅13.
Factor 25 out of 325.
160+8⋅25(13)+20⋅(82)2+(15)2
Rewrite 25 as 52.
160+8⋅52⋅13+20⋅(82)2+(15)2
160+8⋅52⋅13+20⋅(82)2+(15)2
Pull terms out from under the radical.
160+8⋅(513)+20⋅(82)2+(15)2
Multiply 5 by 8.
160+4013+20⋅(82)2+(15)2
Divide 8 by 2.
160+4013+20⋅42+(15)2
Raise 4 to the power of 2.
160+4013+20⋅16+(15)2
Raise 15 to the power of 2.
160+4013+20⋅16+225