2 intersecting lines, one of which is vertical and one of which is horizontal. The intersection forms a right angle.

Intersecting Lines, 2 Perpendicular

2 intersecting lines, one of which is vertical and one of which is horizontal. The intersection forms…

Right angle with square at perpendicular lines

Right Angle

Right angle with square at perpendicular lines

Four types of angles: right, obtuse, acute, and straight.

Angles

Four types of angles: right, obtuse, acute, and straight.

Showing different types of angles: right, acute, and obtuse.

Angles

Showing different types of angles: right, acute, and obtuse.

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

Circle With Inscribed Right Angle in Semicircle

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

Every elliptical involution has the property that there are two definite points in the plane from which any two conjugate points are seen under a right angle.

Circular Involution

Every elliptical involution has the property that there are two definite points in the plane from which…

Circles should be unshaded or shaded evenly with thick and thin lines, changing at about 45 degrees.

Drawing Lines 4

Circles should be unshaded or shaded evenly with thick and thin lines, changing at about 45 degrees.

Projections of a line perpendicular to a plane.

Projections of a Line

Projections of a line perpendicular to a plane.

Right angle at perpendicular lines demonstrated by string on plumb line.

Perpendicular Lines

Right angle at perpendicular lines demonstrated by string on plumb line.

Illustration of perpendicular lines. Intersecting lines that meet at a right angle.

Perpendicular Lines

Illustration of perpendicular lines. Intersecting lines that meet at a right angle.

Illustration of perpendicular lines with the horizontal and vertical lines labeled. "A horizontal line is a line parallel to the horizon, or water level. A vertical line is a line perpendicular to a horizontal line; consequently, it has the direction of a plumb-line."

Perpendicular Lines With Horizontal and Vertical Labeled

Illustration of perpendicular lines with the horizontal and vertical lines labeled. "A horizontal line…

A perpendicular line drawn from point P to straight line RS.

Perpendicular Line Drawn From Point P to Line RS

A perpendicular line drawn from point P to straight line RS.

CD is the projection of AB upon OX. In each case AE=CD and AE=ABcos theta.

Projection of a Line Segment

CD is the projection of AB upon OX. In each case AE=CD and AE=ABcos theta.

A right triangle with degrees 1, 89, 90.

Right Triangle degrees 1, 89, 90

A right triangle with degrees 1, 89, 90.

A right triangle with degrees 10, 80, 90.

Right Triangle degrees 10, 80, 90

A right triangle with degrees 10, 80, 90.

A right triangle with degrees 11, 79, 90.

Right Triangle degrees 11, 79, 90

A right triangle with degrees 11, 79, 90.

A right triangle with degrees 12, 78, 90.

Right Triangle degrees 12, 78, 90

A right triangle with degrees 12, 78, 90.

A right triangle with degrees 13, 77, 90.

Right Triangle degrees 13, 77, 90

A right triangle with degrees 13, 77, 90.

A right triangle with degrees 14, 76, 90.

Right Triangle degrees 14, 76, 90

A right triangle with degrees 14, 76, 90.

A right triangle with degrees 15, 75, 90.

Right Triangle degrees 15, 75, 90

A right triangle with degrees 15, 75, 90.

A right triangle with degrees 16, 74, 90.

Right Triangle degrees 16, 74, 90

A right triangle with degrees 16, 74, 90.

A right triangle with degrees 17, 73, 90.

Right Triangle degrees 17, 73, 90

A right triangle with degrees 17, 73, 90.

A right triangle with degrees 18, 72, 90.

Right Triangle degrees 18, 72, 90

A right triangle with degrees 18, 72, 90.

A right triangle with degrees 19, 71, 90.

Right Triangle degrees 19, 71, 90

A right triangle with degrees 19, 71, 90.

A right triangle with degrees 2, 88, 90.

Right Triangle degrees 2, 88, 90

A right triangle with degrees 2, 88, 90.

A right triangle with degrees 20, 70, 90.

Right Triangle degrees 20, 70, 90

A right triangle with degrees 20, 70, 90.

A right triangle with degrees 21, 69, 90.

Right Triangle degrees 21, 69, 90

A right triangle with degrees 21, 69, 90.

A right triangle with degrees 22, 68, 90.

Right Triangle degrees 22, 68, 90

A right triangle with degrees 22, 68, 90.

A right triangle with degrees 23, 67, 90.

Right Triangle degrees 23, 67, 90

A right triangle with degrees 23, 67, 90.

A right triangle with degrees 24, 66, 90.

Right Triangle degrees 24, 66, 90

A right triangle with degrees 24, 66, 90.

A right triangle with degrees 25, 65, 90.

Right Triangle degrees 25, 65, 90

A right triangle with degrees 25, 65, 90.

A right triangle with degrees 26, 64, 90.

Right Triangle degrees 26, 64, 90

A right triangle with degrees 26, 64, 90.

A right triangle with degrees 27, 63, 90.

Right Triangle degrees 27, 63, 90

A right triangle with degrees 27, 63, 90.

A right triangle with degrees 28, 62, 90.

Right Triangle degrees 28, 62, 90

A right triangle with degrees 28, 62, 90.

A right triangle with degrees 29, 61, 90.

Right Triangle degrees 29, 61, 90

A right triangle with degrees 29, 61, 90.

A right triangle with degrees 30, 60, 90.

Right Triangle degrees 30, 60, 90

A right triangle with degrees 30, 60, 90.

A right triangle with degrees 31, 59, 90.

Right Triangle degrees 31, 59, 90

A right triangle with degrees 31, 59, 90.

A right triangle with degrees 32, 58, 90.

Right Triangle degrees 32, 58, 90

A right triangle with degrees 32, 58, 90.

A right triangle with degrees 33, 57, 90.

Right Triangle degrees 33, 57, 90

A right triangle with degrees 33, 57, 90.

A right triangle with degrees 34, 56, 90.

Right Triangle degrees 34, 56, 90

A right triangle with degrees 34, 56, 90.

A right triangle with degrees 35, 55, 90.

Right Triangle degrees 35, 55, 90

A right triangle with degrees 35, 55, 90.

A right triangle with degrees 36, 54, 90.

Right Triangle degrees 36, 54, 90

A right triangle with degrees 36, 54, 90.

A right triangle with degrees 37, 53, 90.

Right Triangle degrees 37, 53, 90

A right triangle with degrees 37, 53, 90.

A right triangle with degrees 38, 52, 90.

Right Triangle degrees 38, 52, 90

A right triangle with degrees 38, 52, 90.

A right triangle with degrees 39, 51, 90.

Right Triangle degrees 39, 51, 90

A right triangle with degrees 39, 51, 90.

A right triangle with degrees 40, 50, 90.

Right Triangle degrees 40, 50, 90

A right triangle with degrees 40, 50, 90.

A right triangle with degrees 41, 49, 90.

Right Triangle degrees 41, 49, 90

A right triangle with degrees 41, 49, 90.

A right triangle with degrees 42, 48, 90.

Right Triangle degrees 42, 48, 90

A right triangle with degrees 42, 48, 90.

A right triangle with degrees 43, 47, 90.

Right Triangle degrees 43, 47, 90

A right triangle with degrees 43, 47, 90.

A right triangle with degrees 44, 46, 90.

Right Triangle degrees 44, 46, 90

A right triangle with degrees 44, 46, 90.

A right triangle with degrees 45, 45, 90.

Right Triangle degrees 45 45, 90

A right triangle with degrees 45, 45, 90.

A right triangle with degrees, 46, 44, 90

Right Triangle degrees, 46, 44, 90

A right triangle with degrees, 46, 44, 90

A right triangle with degrees, 47, 43, 90

Right Triangle degrees, 47, 43, 90

A right triangle with degrees, 47, 43, 90

A right triangle with degrees, 48, 42, 90

Right Triangle degrees, 48, 42, 90

A right triangle with degrees, 48, 42, 90

A right triangle with degrees, 49, 41, 90

Right Triangle degrees, 49, 41, 90

A right triangle with degrees, 49, 41, 90

A right triangle with degrees 5, 85, 90.

Right Triangle degrees 5, 85, 90

A right triangle with degrees 5, 85, 90.

A right triangle with degrees, 50, 40, 90

Right Triangle degrees, 50, 40, 90

A right triangle with degrees, 50, 40, 90

A right triangle with degrees, 51, 39, 90

Right Triangle degrees, 51, 39, 90

A right triangle with degrees, 51, 39, 90

A right triangle with degrees, 53, 37, 90

Right Triangle degrees, 53, 37, 90

A right triangle with degrees, 53, 37, 90

A right triangle with degrees, 54, 36, 90

Right Triangle degrees, 54, 36, 90

A right triangle with degrees, 54, 36, 90