Question 520172
a = 5cm
b = 6cm
c = ?

Use Pythagorean Theorem

c^2=a^2+b^2
c^2=(5)^2+(36)^2
c^2 = 25 +36
c^2 = 61
Taking sqrt both sides
sqrtc^2 = sqrt61
c=7.81cm

The length of diagonal is 7.81cm