Question

12. In the diagram below…
What is the length of CB?
1) 3.2
2) 4.8
3) 16.2
4) 19.2

Answer 1

Solution

The diagonal of a cuboid is given as

$AB=\sqrt{12^2+3^2+4^2}=13$

Using Pythagoras theorem

$\begin{gathered} CB^2=AB^2-AC^2 \\ \\ \Rightarrow CB=\sqrt{AB^2-AC^2} \\ \\ \Rightarrow CB=\sqrt{13^2-12^2}=5 \end{gathered}$

Correct option is 2