Question

$ABCD$ is a rectangle whose three vertices are $B(4,0),C(4,3)$ and $D(0,3)$. The length of one of its diagonals is

• A. $5$
• B. $4$
• C. $3$
• D. $25$

Answer 1

The correct option is A $5$

From the diagram we can see that AB $=4$ units, BC $=3$ units

Using Pythagoras theorem,

$A{C}^2=A{B}^2+B{C}^2$

$=4^2+3^2$

$A{C}^2=16+9=25$

Taking square root on both the sides, we get

AC $=5$ units.