A rectangular book measures 18 x 9. What is the length of its diagonal?

20.1246118 or 20.12

Step-by-step explanation:

First draw the box with the diagonal, as you can see it is split into 2 equal right triangles.

Now use the pythagorean theorem (a^2+b^2=c^2) to find the length of the diagonal

5.33

11.89

2.49

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