9 Mathematics - Pythagoras and Trigonometry Practice Flashcards

This set of vocabulary flashcards covers the fundamental terms and concepts of Pythagoras' Theorem and Trigonometry as presented in the Scotch College Adelaide 9 Mathematics unit.

Hypotenuse

The longest side of a right-angled triangle, which is always located opposite the right angle.

Pythagoras' Theorem

A theorem stating that the square of the length of the hypotenuse is equal to the sum of the squares of the lengths of the other two sides, expressed as $c^2 = a^2 + b^2$.

Surd

An exact value expressed using a root sign; when written as a decimal, it is an infinite non-recurring decimal with no pattern, such as $\sqrt{2}$, $\sqrt{28}$, or $2\sqrt{3}$.

Exact form

An answer left in its surd form (e.g., $\sqrt{19}$) to maintain precision rather than rounding to a decimal.

Pronumeral

A letter used in an equation to represent an unknown numerical value.

Opposite side

The side across from a particular angle in a right-angled triangle.

Adjacent side

The side next to a particular angle in a right-angled triangle that is not the hypotenuse.

Sin(Angle)

A trigonometric ratio defined as the length of the opposite side divided by the length of the hypotenuse.

Cos(Angle)

A trigonometric ratio defined as the length of the adjacent side divided by the length of the hypotenuse.

Tan(Angle)

A trigonometric ratio defined as the length of the opposite side divided by the length of the adjacent side.

Inverse sine ($\sin^{-1}$)

A trigonometric operation used to find an angle when the lengths of the opposite side and the hypotenuse are known.

Inverse cosine ($\cos^{-1}$)

A trigonometric operation used to find an angle when the lengths of the adjacent side and the hypotenuse are known.

Inverse tangent ($\tan^{-1}$)

A trigonometric operation used to find an angle when the lengths of the opposite side and the adjacent side are known.

Angle of elevation

The angle measured upwards from the horizontal level to the line of sight of an object above.

Angle of depression

The angle measured downwards from the horizontal level to the line of sight of an object below.