The distance from the center of the circle 0 to the middle of the chord AB is equal to the root 41. Find the radius of the circle

The distance from the center of the circle 0 to the middle of the chord AB is equal to the root 41. Find the radius of the circle if the length of the chord AB = 40.

Given: AB (chord) = 40; OH = √41;
Find: R- ?;
Decision.
Draw a circle with AB and OH on it. Connect points A and O into a segment AO – the radius of the circle. Also AO is one of the sides of the OHA triangle. Note that the angle of SHE is straight, that is, it is equal to 90 degrees. Hence the triangle SHE is rectangular. The OH side is equal to half AB: OH = 40: 2 = 20
We know the sides AH and OH, as well as the angle OHA, which means that we can find the side of AO by the Pythagorean theorem: a ^ 2 + b ^ 2 = c ^ 2
(AH) ^ 2 + (OH) ^ 2 = (AO) ^ 2
20 ^ 2 + √41 ^ 2 = AO ^ 2
AO ^ 2 = 400 + 41
AO ^ 2 = 441
AO = √441
AO = 21
Answer: 21.