2001 mein kaise questions aa rahe the bhai 😭

Im so glad we weren't born 24 years earlier, cos this is a question from 2001:

A vertical tower is 20m high. A man standing at some distance from the tower knows that the cosine of the angle of elevation of the top of the tower is 0.53. How far is he standing from the foot of the tower?

This needs Pythagorean theorem, trig knowledge AND a square root table to solve 😭😭
(or it could also be done without Pythagorean but too many decimals arghhhh)