## Objective(s)

- Create diagrams using a straightedge
- Use a compass to construct a circle

Required materials: compass, straightedge, patty paper

## Warm Up

Gain familiarity with the construction tools by drawing multiple lines and circles. Then, follow these steps:

- Draw a point, label it
- Draw a circle centered at
- Mark a point on the circle, label it
- Draw a circle centered at going through
- Draw segment

### Definitions

**Line segment**: a set of points on a line with two endpoints

**Circle**: a set of all points that are the same distance (radius) from a given point (center)

## Illegal Moves

Given segment , follow these steps:

- Draw a circle centered at with radius
- Mark a point at the middle of , label it
- Draw a circle centered at with radius
- Label the intersection above as and below as
- Draw segments , , and , and trace onto patty paper

### Discussion

Compare your with your neighbors.

Why might they be different? How could we ensure they are all the same?

### Valid Construction Moves

- Draw points in blank space, on objects, and at intersections
- Draw segments, rays, and lines through two points
- Draw a circle centered at a point and through another point
- Set compass to a length between two points then move the compass

## Perfect Copy

The figure shows the first few steps of constructing a regular hexagon. Complete the construction.

(image)

### Reflection

How does your regular hexagon compare to your neighbors?

A **regular polygon** has sides with equal lengths. How can you be sure your hexagon is a regular hexagon?

## Summary

A straightedge can be used to create line segments. Line segments are named by its endpoints.

A compass can be used to create circles. Circles are named by its center and radius.