Question

find the length of a diagonal of a square with sides 10in long

Answer 1

a^2 + b^2 = c^2

10^2 + 10^2 = c^2

100 + 100 = c^2

200 = c^2

c^2 = 200

c = sqrt(200)

c = sqrt(100*2)

c = sqrt(100)*sqrt(2)

c = 10*sqrt(2)



So the diagonal is 10*sqrt(2) inches long.