question_answer

The vertices of the rectangle ABCD are\[A(-1,\]\[0),\]\[B(2,\text{ }0),C(a,\text{ }b)\]and\[D(-1,\text{ }4)\]Then, the length of the diagonal AC is

A)  2                            

B)         3

C)  4                            

D)         5

E)  6

Correct Answer: D

Solution :

Length of diagonal BD \[=\sqrt{{{(2+1)}^{2}}+{{(0-4)}^{2}}}\] \[=\sqrt{9+16}\] \[=\sqrt{25}=5\]