Question

if the area of a square is 72ftsquare , find the length of its diagonals

Answer 1

Answer:

Step-by-step explanation:

Given :  

nth term , an= An + B………….(1)

On putting n = 1 in eq 1,

a1 = A + B

On putting n = 20 in eq 1,

a20 = A × 20 + B

a20 = 20A + B

a20 = l(last term)  = 20A + B

By using the formula ,Sum of nth terms , Sn = n/2 [a + l]

S20 = 20/2 [a + l]

S20 = 10 [A + B + 20A + B]

S20 = 10 [21A + 2B]

S20 = 210A + 20B

Hence, the sum of first 20 terms of the given  sequence is 210A + 20e

Step-by-step explanation:

Answer 2

Answer:

12cm

Step-by-step explanation:

let side be =x

area of square = x^2=72

x=2√72

x=6√2

let length of the diognals =y

x2 + x2 = y2

y2 = (6√2)2 + (6√2)2

y2= 72 +72

y2= 144

y=√144

y = 12