3D Trigonometry


A collection of videos, solutions, activities and worksheets that are suitable for GCSE Maths.




Share this page to Google Classroom

Related Pages
Trigonometric Graphs
Lessons On Trigonometry
Trigonometry Worksheets
More Math Lessons for GCSE

How to solve problems that involve 3D shapes using trigonometry and the Pythagoras' Theorem?

The following diagram gives an example of the projection of a line on a plane and the angle between a line and and plane. Scroll down the page for more examples and explanations on using Trigonometry and the Pythagoras' Theorem to solve 3D word problems.

3d trigonometry

GCSE Maths 3 D Trigonometry A* Question

Example:
ABCDEFG is a solid cuboid.
a) Find the length BE
b) Calculate the angle that BH makes with the plane ABFE.

IB Math Studies: 3D Trigonometry

Examples:

  1. A room is in the shape of a cuboid. Its floor measures 7.2m by 9.6m and its height is 3.5m.
    a) Calculate the length of AC
    b) Calculate the length of AG
    c) Calculate the angle that AG makes with the floor.
  2. The right pyramid shown in the diagram has a square base with sides of length 40 cm. The height of the pyramid is also 40 cm.
    a) Find the length of OB.
    b) Find the size of angle OBP.



Trigonometry and Pythagoras in 3D Shapes
Calculating an angle between an edge and plane in a 3D shape using Pythagoras and trigonometry.

Example:
For this cuboid calculate
a) Length AG
b) Angle between AG and the plane ABCD

Angle between a line and a plane
AddMaths Ex8A Q1

3D Trigonometry Problem
The worked solution to a three-dimensional trigonometry problem.
A tree on the far side of a river bank is used to determine the width of the river with the help of a few right angle triangles.
Step 1: Identify the right angles in your diagram.
Step 2: Include all the measurements in your diagram.



How to do Trigonometry in Three dimensions?
3D trig Pythagoras cuboid Part 1

Example:
ABCDEFGH is a cuboid with dimensions 4m, 2m and 1.5m. X is the midpoint of the side EF. Find the lengths AC, AG and AX. Find the angles GAC and AXB.

3D Trig Pythagoras cuboid part 2.

3D Trig Pythagoras cuboid part 3.

3D Trig Pythagoras cuboid part 4.

3D Trig Pythagoras cuboid part 5.



Check out our most popular games!

Fraction Concoction Game:
Master fractions in the lab: mix, add, and subtract beakers to create the perfect concoction!

Fraction Concoction Game

Fact Family Game:
Complete fact families and master the link between addition & subtraction and multiplication & division.

Fact Family Game

Number Bond Garden:
Clear the board by matching number pairs that sum to ten in this garden-themed mental math puzzle.

Number Bond Garden

Online Addition Subtraction Game:
Practice your addition and subtraction skills to help the penguin find its mummy.

Online Addition Subtraction Game



We welcome your feedback, comments and questions about this site or page. Please submit your feedback or enquiries via our Feedback page.