# ABCD is a rectangle whose three vertices are B(4, 0), C(4, 3) and D(0, 3).

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

Solution:

Here, AC and BD are two diagonals of the rectangle ABCD. So

$B D=\sqrt{(4-0)^{2}+(0-3)^{2}}$

$=\sqrt{(4)^{2}+(-3)^{2}}$

$=\sqrt{16+9}$

$=\sqrt{25}$

$=5$ units

Hence, the correct answer is option (a).