This guide offers many suggestions for practical surveying tasks that can be done without needing any expensive equipment. Applications of trigonometry include measuring the length of your shadow and relating this to the angle of elevation of the sun and the time of day, measuring heights of buildings, trees and towers, navigation, […]
This workshop reviews reduction formulae in terms of rotations and reflections. It offers learning activities that involve sorting and solving trigonometric equations and finding general solutions, or solutions within a
given domain, using known identities and graphical or unit circle representations. Suggestions are given organising group activies and learners presenting and explaining their ideas […]
The area of triangle PQR is 3√3 square centimetres. Angle PRQ is 60 degrees and RQ is 4 centimetres longer than PR.
Find the length of PQ.
Draw ΔPQR accurately.
Calculate all the angles in the triangle.
The Great Pyramid at Giza in Egypt was built around 2500 BC. The pyramid has a square base ABCD with sides 232.6 metres long. The distance from each corner of the base to the apex E was originally 221.2 metres.
Draw a diagram of the pyramid to show two right angled triangles […]
DO NOT USE CALCULATORS FOR THIS WHOLE CLASS ACTIVITY.
YOU NEED TO KNOW: that the cosine and sine functions for ALL ANGLES are given by the coordinates of points on the UNIT CIRCLE. The x-coordinates of points on the unit circle give the cosine of the angle between the x-axis and the radius measured anti-clockwise […]
The Cape Town cable car takes tourists to the top of Table Mountain. The cable is 1.2 kilometres in length and makes an angle of 40 degrees with the ground. Calculate the vertical height (h) climbed by the cable car.
If the lower cable car station is 3o2 metres above sea level, […]
What does Pythagoras Theorem tell you about these angles?
Use this information to find this sum of squares of sines:
This problem is adapted from the NRICH task Degree […]
How could I make graph 2 from graph 1? Can you work out the equation of graph 2?
Graph 3 has equation y=sin2x. […]
Two ships are heading towards a lighthouse on the same path, one behind the other. From a height of 42 metre the closer ship is observed at an angle of depression θ where tan θ = ⅘ and the other ship at an angle of depression of 30 degrees. Draw a diagram.
A climber is stuck on a cliff face. A rescue worker on the ground is 200 m from the bottom of the cliff. The angles of elevation of the climber and of the top of the cliff as seen by the rescuer are 45 degrees and 60 degrees respectively. Draw a diagram.