Question

What is the length of AB?

√53
5
2√10
2√6

Answer 1

$\sqrt{ {4}^{2} + {6}^{2} } = 2 \sqrt{13}$
$\sqrt{ {(2 \sqrt{13} )}^{2} + {1}^{2} } = \sqrt{53}$
The answer is
$\sqrt{53}$
using pythagoras' theorem