adjacent side

The side next to the reference angle in a right triangle. The adjacent side cannot be the hypotenuse.

CAH

Cosine is adjacent over hypotenuse.

cosecant

In a right triangle, the ratio of the length of the hypotenuse divided by the opposite side of the angle. Cosecant is the reverse of sine.

cosine

In a right triangle, the ratio of the length of the side adjacent to the angle divided by the hypotenuse.

cotangent

In a right triangle, the ratio of the length of the adjacent side divided by the length of the opposite side of the angle. Cotangent is the reverse of tangent.

hypotenuse

The longest side of a right triangle. The hypotenuse is always opposite the 90° angle in a right triangle.

included angle

The entire angle that contains the taper. Each edge of the taper forms a leg of the angle.

minute

A unit of measurement used to describe angles. There are 60 minutes in 1 degree.

opposite side

The side across from the reference angle in a right triangle.

reference angle

The measured, or known angle in a right triangle other than the 90° angle.

right triangle

A triangle containing one angle that measures exactly 90 degrees.

secant

In a right triangle, the ratio of the length of the hypotenuse divided by the adjacent side of the angle. Secant is the reverse of cosine.

second

A unit of measurement used to describe angles. There are 60 seconds in 1 minute and 60 minutes in 1 degree.

sine

In a right triangle, the ratio of the length of the side opposite the angle divided by the hypotenuse.

SOH

Sine is opposite over hypotenuse.

SOHCAHTOA

A common phrase that helps visualize the relationship between the trigonometric ratios. Each letter represents the ratios in order.

symmetrical

A quality in which all the features on either side of a point, line, or plane are identical. Both sides of a symmetrical part have the same dimensions.

tangent

In a right triangle, the ratio of the length of the side opposite the angle divided by the length of the adjacent side.

taper

A conical object with a gradual decrease in diameter from one end to another. On a shop print, a taper forms a right triangle.

taper per foot

A measurement unit for a taper indicating the change in diameter for each foot along the taper's length.

TOA

Tangent is opposite over adjacent.

trigonometric ratio

A ratio that describes a relationship between the sides and angles of a triangle.
