Illustration of a circle used to prove "Any angle inscribed in a segment less than a semicircle is an…

Illustration of a circle with an angle inscribed in a segment greater than a semicircle, an acute angle.

Illustration of a circle with an angle inscribed in a segment less than a semicircle, an obtuse angle.

Illustration of a circle with a right angle inscribed in a semicircle.

Illustrations of a circle with segment, semicircle, sector, quadrant, and central angles drawn.

Circular design made by rotating circles about a fixed point. The radii of the smaller circles is equal…

Circular design made by rotating circles about a fixed point. The radii of the smaller circles is equal…

Illustration of a circle used to prove "Any angle inscribed in a semicircle is a right angle."

Illustration of a sphere generated by the revolution of a semicircle ACB about its diameter AB as an…