# How to make: a hyperbolic plane

A great way to waste a lot of paper

#### You will need

• triangle paper
• scissors
• sticky tape

#### Instructions

1. Cut out a hexagon and a triangle from the triangle paper.

2. Cut along one of the lines from a corner of the hexagon to the centre.

3. Tape the triangle between the two edges of the cut you just made. There is now more than 360° around the point, so the surface will not be flat.

4. Continue to tape more triangles to the surface, making sure there are always seven triangles at each point.

5. Congratulations! You have made a hyperbolic surface.

• ### Modelling in a heartbeat

Learn how to model your heart one beat at a time ❤️
• ### Math Blaster

Belgin plays a classic mathsy game from her childhood...in 16-bit graphics! Here's her review...
• ### Why Knot?

You can un-knot a knot, by cutting it not?
• ### Surname Extinction

Why do surnames die out? We take a look at the Galton-Watson process for modelling the extinction of surnames to answer the question: 'When will we all be Smiths?'
• ### Crossnumber winners, Issue 06

Did you solve it?
• ### Well, well, well…

A fiendish puzzle for you to 'pour' over...