Nata) The formula S-
gives the partial sum of an arithmetic sequence. What is the formula solved for an?
2S-a, n
o a
2S+a,
n
O a, - 2S+an+n
O a, = 2S-a, n+n

ab will be equal to

the answer is:

the lateral area is equal to

to find the lateral area of the square pyramid, first we need to find the perimeter of the base, and then, find the lateral area using the following formulas:

where,

s, is the base length

slant height, is the height of a the side of the pyramid

we are given:

now, calculating the perimeter of the base, we have:

then, calculating the lateral area:

hence, we have that the lateral area is equal to

have a nice day!