Tools of the trade
Every profession has particular tools that they use all the time, a chef has their knives, the sewer a machine and the mathematician, well they have their construction tools.
No, not hammers and hard hats - Mathematicians use a compass, pencil and a ruler.
From just these three things we can create (nearly) all of what we require in geometry.
A great Greek mathematician named Euclid, who is credited to have written the first mathematics textbook over 2000 years ago, went to great lengths to detail many of the mathematical constructions we will look at today. Geometrical constructions were so important to mathematics at the time because most problems were solved graphically, not arithmetically.
Construct a circle
To construct a circle with a particular radius with a compass, follow the instructions below.
Steps for construction
- Put a pencil in your compass if there is not one in there already.
- Set the compass width to the length of your required radius.
- Put the point end of the compass on the paper.
- Rotate the pencil end of the compass on the paper all the way around to make a full circle.
Activity 1
Use the above steps to construct a circle with radius of 3\text{ cm}.
Activity 2
Use the above steps to construct a circle with radius of 2 \text{ cm}.
Activity 3
Use the above steps to construct a circle with diameter of 5\text{ cm}.