ANSWER
24.1 cm
EXPLANATION
First, let us make a sketch of the question:
We see that the diagonal and the sides of the rectangle form two equal right angled triangles.
To find the length of diagonal, we have to apply Pythagoras Rule:
[tex]\text{hyp}^2=a^2+b^2[/tex]where hyp = hypotenuse = D
a and b = legs of the triangles (16 cm and 18 cm)
So, we have that:
[tex]\begin{gathered} D^2=16^2+18^2 \\ D^2\text{ = 256 + 324} \\ D^2\text{ = 580} \\ Find\text{ the square root of both sides:} \\ D\text{ = }\sqrt[]{580} \\ D\text{ }\cong24.1\text{ cm} \end{gathered}[/tex]The length of the diagonal is 24.1 cm.
