Answer:
A semicircle has an angle measure of 180°.
Explanation:
In order to obtain the correct answer we need to recall that the angle measure of the circle is 360°, which is a complete angle. Now, we draw a diameter with the goal to have a semicircle, notice that the circle is divided in exactly two identical pieces. So, the angle measures of the two sides should be the same, which is the half of a complete angle: 360°/2=180°. Hence, the angle of a semicircle is a straight angle.