What number has the square root of 80?

Answer 1

sqr80 = sqr16(sqr5) = 4sqr5 = about 4(2.236) = 8.944

8.944 squared = a little over 79.995 rounded of to three decimal places

square root of 80 = exactly 4sqr5.

4sqr5 squared = 4^2 x (sqr5)^2 = 16 x 5 = exactly 80

or use a calculator with a square root function:

square root of 80 = 8.94427191... which is a non-repeating decimal, an irrational number

you know the square root of 81 is 9, as 9^2 = 81, so square root of 80 is slightly less than 9