SOLUTION: the perimeter of a square is 20 centimeter. Find the length of a diagonal. Round answer to the nearest tenth.

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Question 287351: the perimeter of a square is 20 centimeter. Find the length of a diagonal. Round answer to the nearest tenth.
Found 2 solutions by texttutoring, richwmiller:
Answer by texttutoring(324) About Me  (Show Source):
You can put this solution on YOUR website!
If the perimeter is 20cm, that means that each side must be 5cm (because the sides are equal in a square, and it has four sides: 5+5+5+5=20)
Use Pythagorean Theorem to find the diagonal:
a%5E2%2Bb%5E2=c%5E2
5%5E2%2B5%5E2=c%5E2
25%2B25=c%5E2
50=c%5E2
c=sqrt%2850%29
c=7.07

Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
perimeter =4s=20
s=5
the diagonal is the hypotenuse with legs both 5
2*5^2=50
sqrt(50)=sqrt(5*5*2)=5sqrt(2)
sqrt(2)=1.414