Illustration of a circle with a sector. "A sector of a circle is the space included between an arc and…

Illustration of a sector of a circle. A sector is the space between an arc and two radii drawn to the…

Illustration of a sector of a hollow circle. A sector is the space between an arc and two radii drawn…

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

An illustration showing a circle sector with radius r, center/central angle v, and length of circle…

An illustration showing a circle sector with center/central angle v and polygon angle w.

Diagram showing 2 superimposed symmetrical spherical triangles.

In this illustration, "the driven surface of the slide coincides with the tangent to the spiral, the…

An illustration showing a circle with sectors D and E inscribed in a triangle with angles, A, B, and…

Diagram showing a spherical triangle constructed by the intersection of polar arcs.

Diagram showing a spherical triangle constructed by the intersection of polar arcs.

Diagram showing a spherical triangle constructed by the intersection of polar arcs.