Non-Right Angled Trigonometry

Question 1

Formula

sinθ =

Answer 1

sinθ = opposite/hypotenuse

SOH

Question 2

Formula

cosθ =

Answer 2

cosθ = adjacent/hypotenuse

CAH

Question 3

Formula

tanθ =

Answer 3

tanθ = opposite/adjacent

TOA

Question 4

Define

Compass Bearings

Answer 4

Use the four points of a compass rose to determine the placement of an object. Angles are measured from North or South and take the form “N/S [angle] E/W. (e.g. S45°W, 45°W of S.)

Question 5

Defines

True Bearings

Answer 5

A bearing measured in a clickwise direction from N, written with leading zeros and noted as “T”. (e.g. a compass bearing of N55°E would be 055°T.)

Question 6

Formula

tan (180°–θ) =

Answer 6

-tan θ

Question 7

Formula

cos (180°–θ) =

Answer 7

-cos θ

Question 8

Formula

sin (180°–θ) =

Answer 8

sin θ

Question 9

Formula

Area of a Triangle

(angle and two sides)

Answer 9

A = 1/2ab x sinC

Area = 1/2 x side a x side b x sin(angle C)

Question 10

You are given two sides and their opposite angles (including the side/angle that needs to be found).

Answer 10

sinA/a = sinB/b = sinC/c

Sine Rule

Question 11

You are given three sides, and need to find an angle.

Answer 11

Cos(C) = a^2 + b^2 - c^2 / 2ab

Cosine Rule

Question 12

You have been given two sides and the included angle, and need to find the third side.

Answer 12

c^2 = a^2 + b^2 - 2ab x cos(C)

Cosine Rule