Summary
Constructions in geometry involve using tools to create precise shapes and angles. These tools include a protractor, compass, and ruler.
- Protractor — a tool used to measure angles. Example: Used to measure a 70° angle.
- Compass — a tool used to draw arcs and circles. Example: Used to bisect a line or angle.
- Ruler — a tool used to draw straight lines and measure lengths. Example: Used to draw a line segment of 5cm.
Exam Tips
Key Definitions to Remember
- A protractor is used to measure angles.
- A compass is used to draw arcs and circles.
- A ruler is used to draw straight lines and measure lengths.
Common Confusions
- Confusing the use of a compass with a protractor.
- Forgetting to label points when constructing lines or angles.
Typical Exam Questions
- How do you construct a line segment of 5cm? Use a ruler to draw a straight line and measure 5cm.
- How do you construct a 70° angle? Use a protractor to measure and draw a 70° angle.
- How do you bisect a line perpendicularly? Use a compass to mark equal distances from the line and draw a perpendicular bisector.
What Examiners Usually Test
- Ability to use a compass and protractor correctly.
- Accuracy in constructing lines and angles.