Find the degree measure of the angle ACO, if the beam CA touches the circle centered at point O

Find the degree measure of the angle ACO, if the beam CA touches the circle centered at point O, and the degree measure of the smaller arc of this circle, enclosed inside the angle ACO, is 50 degrees.

The tangent to the circle forms an angle of 90 degrees with a radius, which means a triangle

AOC is rectangular.

The SOA corner is central. It is equal to the degree measure of the arc enclosed between its sides,

that is, <COA = 50 °.

The sum of two acute angles, if the third is 90 degrees, equals 90 °, then

<ACO = 90 ° – 50 ° = 40 °.