Triangle Trigonometry flashcards

50 practice cards drawn from the Triangle Trigonometry lessons. Tap a card to turn it over. Every answer is checked against the lesson it came from.

Read the Triangle Trigonometry lessons in full →

Which ratio is opposite over hypotenuse?

sine

from “Sine, Cosine and Tangent”

Which ratio is opposite over adjacent?

tangent

from “Sine, Cosine and Tangent”

What is cos 45°?

1/√2

from “Exact Sine, Cosine and Tangent at 30, 45 and 60°”

What is tan 60°?

√3

from “Exact Sine, Cosine and Tangent at 30, 45 and 60°”

cos 12° equals which sine?

sin 78°

from “Sine and Cosine of Complementary Angles”

cos 25° equals which sine?

sin 65°

from “Sine and Cosine of Complementary Angles”

A right triangle has hypotenuse 18 and an angle of 30°. How long is the opposite side?

9

from “Solving Right Triangles”

A right triangle has hypotenuse 16 and an angle of 30°. How long is the opposite side?

8

from “Solving Right Triangles”

sin θ = 1/2. What is θ?

30°

from “Finding an Angle from a Ratio”

The opposite side is 5 and the adjacent is 2. Which expression gives the angle?

tan⁻¹(5 / 2)

from “Finding an Angle from a Ratio”

Standing 35 m away, the angle of elevation to the top is 30°. How tall is it?

35/√3 m

from “Elevation and Depression”

From a cliff 49 m high, the angle of depression to a boat is 45°. How far out is it?

49 m

from “Elevation and Depression”

What is cos 150°?

−√3/2

from “Sine and Cosine of Angles Past 90 Degrees”

What is cos 120°?

−½

from “Sine and Cosine of Angles Past 90 Degrees”

Where does sin x reach its highest value between 0° and 360°?

90°

from “The Graphs of Sine and Cosine”

The sine wave repeats itself every…?

360°

from “The Graphs of Sine and Cosine”

Between 0° and 180°, where does tan x have no value?

90°

from “The Graph of Tangent”

Between 90° and 180°, tan x is…

negative

from “The Graph of Tangent”

What is the greatest value of y = 2 sin x + 7?

9

from “Amplitude and the Principal Axis”

What is the greatest value of y = 5 sin x + 6?

11

from “Amplitude and the Principal Axis”

How many whole waves does y = sin 5x draw between 0° and 360°?

5

from “The Period and Phase Shift of a Wave”

Which way does y = sin(x − 60°) slide?

60° right

from “The Period and Phase Shift of a Wave”

cos x = cos 80°. Which other angle below 360° agrees?

280°

from “Solving Simple Trigonometric Equations”

sin x = ½. One answer is 30°. What is the other between 0° and 360°?

150°

from “Solving Simple Trigonometric Equations”

tan⁻¹(−1)

−45°

from “The Principal Values of the Inverse Functions”

sin⁻¹(0.5)

30°

from “The Principal Values of the Inverse Functions”

Solve tan²x − tan x = 0 for 0° ≤ x < 360°.

0°, 45°, 180°, 225°

from “Quadratic Equations in Sine, Cosine or Tangent”

Solve 2cos²x + 3cos x − 2 = 0 for 0° ≤ x < 360°.

60°, 300°

from “Quadratic Equations in Sine, Cosine or Tangent”

Solve sin 2x = ½ for 0° ≤ x ≤ 360°.

15°, 75°, 195°, 255°

from “Trigonometric Equations with a Multiple Angle”

Solve sin 3x = 0 for 0° ≤ x ≤ 180°.

0°, 60°, 120°, 180°

from “Trigonometric Equations with a Multiple Angle”

A tide is d = 5 + 3 sin(30t)° with t in hours. How long from one high tide to the next?

12 hours

from “Modeling Tides and Daylight with a Sine Function”

A tide is d = 5 + 3 sin(30t)°. When in the first 6 hours is the depth 6.5 meters?

t = 1 and t = 5

from “Modeling Tides and Daylight with a Sine Function”

Two sides are 2 and 6, with 30° between them. What is the area?

3

from “Area with Sine”

Two sides are 3 and 4, with 30° between them. What is the area?

3

from “Area with Sine”

Side 12 faces 30°, and another angle is 45°. How long is the side facing 45°?

12√2

from “The Sine Rule”

Side 7 faces 30°, and another angle is 45°. How long is the side facing 45°?

7√2

from “The Sine Rule”

Two sides are 8 and 6, with 60° between them. What is the third side squared?

52

from “The Cosine Rule”

Sides 5 and 3 hold the angle C, and the side facing C is 7. What is cos C?

−½

from “The Cosine Rule”

Side 7 faces 30°, and a side of 7√2 faces the angle B. What is B?

45°

from “Finding Angles with the Sine Rule”

Side 8 faces 30°, and a side of 8√2 faces the angle B. What is B?

45°

from “Finding Angles with the Sine Rule”

sin B = ½. Which two angles are the candidates for B?

30° and 150°

from “The Ambiguous Case of the Sine Rule”

sin B = √3/2 names which pair of candidates?

60° and 120°

from “The Ambiguous Case of the Sine Rule”

A triangle has sides 3 and 5 around the angle C, and 7 facing it. What is C?

120°

from “Finding Angles with the Cosine Rule”

A triangle has sides 5 and 8 around the angle C, and 7 facing it. What is C?

60°

from “Finding Angles with the Cosine Rule”

Which three sides make the flat triangle holding that angle?

floor diagonal, height, space diagonal

from “Trigonometry in Three Dimensions”

A floor measures 6 by 8. How long is its diagonal?

10

from “Trigonometry in Three Dimensions”

The hypotenuse is 14 and the angle is 45°. What is the opposite side, exactly?

7√2

from “Exact Trigonometric Ratios with Surds”

The hypotenuse is 12 and the angle is 45°. What is the opposite side, exactly?

6√2

from “Exact Trigonometric Ratios with Surds”

A ship sails 15 km on bearing 050°, then 7 km on 170°. How far is it back to A?

13 km

from “Bearings with the Sine and Cosine Rules”

A ship sails 7 km on bearing 060°, then 8 km on 120°. How far is it back to A?

13 km

from “Bearings with the Sine and Cosine Rules”

Practice these in the app — your progress saves there.