Here are the answers to the questions:

38. The measure of an angle formed by two tangents is equal to the difference between 180° and the intercepted arc.

39. An angle inscribed in a semicircle is a right angle (90°).

40. The measure of a central angle is equal to the measure of its intercepted arc.

41. The measure of an angle formed by a tangent and a secant is equal to half the difference of the intercepted arcs.

42. The measure of an inscribed angle is equal to half the measure of its intercepted arc.

Would you like more explanation for any of these answers or additional examples? Here are some related questions:

1. How do you calculate the intercepted arc in a circle geometry problem?
2. What is the difference between central and inscribed angles in terms of geometry?
3. Can you explain why an angle inscribed in a semicircle is always a right angle?
4. How do the properties of a tangent and a secant interact in geometry?
5. What are some real-life applications of understanding angles in circles?

Tip: Always draw a diagram when solving geometry problems with circles. Visualizing the relationships helps in understanding