I think this is right. Hope it helps
Answer:
m(∠C) = 18°
Step-by-step explanation:
From the picture attached,
m(arc BD) = 20°
m(arc DE) = 104°
Measure of the angle between secant and the tangent drawn from a point outside the circle is half the difference of the measures of intercepted arcs.
m(∠C) = ![\frac{1}{2}[\text{arc(EA)}-\text{arc(BD)}]](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7D%5B%5Ctext%7Barc%28EA%29%7D-%5Ctext%7Barc%28BD%29%7D%5D)
Since, AB is a diameter,
m(arc BD) + m(arc DE) + m(arc EA) = 180°
20° + 104° + m(arc EA) = 180°
124° + m(arc EA) = 180°
m(arc EA) = 56°
Therefore, m(∠C) = 
m(∠C) = 18°
So the easiest way to solve this is to use the straight line provided .
180=90+61+x
180=151+x
29=x
The answer is A because you turn the fraction in a decimal then divide by 5