Given the figure of a circle
The measure of the arc a will be calculated as follows:
[tex]a+53+86=180[/tex]
Solve for a:
[tex]\begin{gathered} a+139=180 \\ a=180-139=41 \end{gathered}[/tex]
The measure of the inscribed angle is half the measure of the arc opposite to it
So, the measure of angle b = 0.5 x 53 = 26.5
And the measure of the angle c = 0.5 x a = 0.5 x 41 = 20.5
