Find the lateral surface area of the figure
below.
9 ft
8 ft
10 ft
4 ft

We generally know consecutive even integer numbers are 2 , 4 , 6, 8, 10 ............

So we can see there is difference of 2 in consecutive even integer.

So if we let first even integer as 2n.

So we will let three consecutive even integer as 2n , 2n+2 , 2n+4

Their sum is 54.

So we can write






So n = 8.

So the first number = 2n = 2*8 = 16

            second number = 2n+2 = 16+2 = 18

            Third number   = 2n+4 = 16+ 4 =20