Illustration that can be used to show the definition of an angle - an opening between two lines that…

A diagram illustrating the airplane's angle of incidence at axis A, direction of motion and thrust.

The diagram illustrating the plane's angle of incidence pointing down at the motion axis. The plan will…

Illustration used to show how to "draw a straight line through any given point on a given straight line…

An illustration showing an angle the is less than a right angle. This is an acute angle.

Illustration to show that if an angle is bisected, and if a line drawn through the vertex perpendicular…

Illustration to show that the bisectors of two supplementary adjacent angles are perpendicular to each…

Illustration to show that the bisector of one of two vertical angles bisects the other.

Illustration to show that the bisector of two pairs of vertical angles formed by two intersecting lines…

Illustration of a dihedral angle bisected by a plane. "Every point in a plane which bisects a dihedral…

Illustration to show that the bisector of the vertical angle of an isosceles triangle bisects the base,…

Illustration to show that if through any point in the bisector of an angle a line is drawn parallel…

Illustration of a convex polyhedral angle. "The sum of the face angles of any convex polyhedral angle…

Diagram used to prove the theorem: "The sum of the face angles of any convex polyhedral angle is less…

Illustration showing the golden angle. The golden angle is the smaller of two angles created by dividing…

Illustration used to show "The two perpendiculars to the sides of an angle from any point in its bisector…

Illustration used to show "The two perpendiculars to the sides of an angle from any point not in its…

Illustration of polyhedral angle. "The opening of three or more planes which meet at a common point…

An illustration showing a straight angle. When the sides of an angle extend in opposite directions,…

An illustration showing acute, obtuse, straight, right, and reflex angles.

An illustration of two angles that are adjacent. They have the same vertex and a common side between…

Illustration of 3 equal dihedral angles. "Two dihedral angles have the same ratio as their plane angles."

Illustration used to show that two trihedral angles are equal or symmetrical when the three face angles…

An illustration showing an angle the is greater than a right angle and less than a straight angle. This…

An illustration showing when one straight line meets another straight line and makes the adjacent angles…

Angles used to illustrate the sum and difference of two angles and trig identities.

Illustration of the superposition of two angles to compare magnitudes of the same kind.

Illustration of supplementary angles. Two angles whose sum is a straight angle.

Illustration of supplementary angles. Two angles whose sum is a straight angle. This can be used tow…

Illustration of supplementary angles. Two angles whose sum is a straight angle. This can be used tow…

Illustration that can be used to show supplementary angles. The angles form a straight line.

Diagram used to prove the theorem: "Two trihedral angles, which have three face angles of the one equal…

Lines drawn to horizontal to form triangle ratios (reference triangles, angles).

Lines drawn to horizontal to form triangle ratios (reference triangles, angles). Axes, quadrants, abscissa,…

Vertical angles are when two angles have the same vertex, and the sides of the one are prolongations…

Illustration of two angles whose sides are parallel, each to each, to show they are either equal or…

Illustration showing arcs measured in positive and negative angles.

Illustration showing that the bisector of a given angle is the locus of points equidistant from the…

Illustration showing that the perpendicular bisector of a given line is the locus of points equidistant…

This gas chandelier is made out of metal and has a bold style with curves and angles.

Illustration of a circle used to prove "All angles inscribed in the same segment are equal."