We can now start to tackle 3D problems using our trigonometric identities. These can be a little more difficult as we can only draw a 2D representation of a 3D solid and have to visualise where certain lines go. Often to calculate the length of a diagonal of a solid we will first need to calculated a diagonal of one of the faces of the solid.

Example

Exercise

Let’s complete exercise 7 on pages 221 to 222 of the textbook:

The answers are below:

Further Questions

Answers