Question

A ladder 4m long is leaning against a wall. The foot of the ladder is not securely held and slips 20 cm further away from the wall. How far does the top of the ladder move down the wall?

Answer 1

$4 { }^{2} = 0.2 {}^{2} + x {}^{2}$
16-0.04=x2
15.96
$\sqrt{15.96}$
3.9m