The diagonal of a square is 3 feet long. Find its perimeter.

My answer:

a^2+b^2=c^2

x^2+x^2=3^3

2x^2=9 divide both side by 2

x^2=4.5

x=√4.5
x=2.1 feet

Is this right?

2 answers

Obviously the perimeter cannot be shorter than one of its sides.

2.1 is the length of each of its sides.

Now find the perimeter.
how can the perimeter be less than the diagonal?

you found one of the sides...the perimeter is all four