What Have We Discussed

1. Measuring Tools: The instruments used to compare and draw line segments are ruler and .

2. Length Measurement: The unit of measuring length is 1 centimeter (1 cm), where 1 cm = mm.

3. Protractor Usage: A protractor is a semi-circular tool with equal divisions used to measure and construct angles.

4. Angle Measurement: The unit of measuring an angle is a degree (1°), which is 1360th of one completehalf rotation.

5. Right and Straight Angles: A right angle measures °, while a straight angle measures °.

6. Acute Angle: An angle is acute if its measure is less than °.

7. Obtuse Angle: An angle is obtuse if its measure is greater than ° but less than °.

8. Reflex Angle: An angle is reflex if its measure is greater than ° but less than °.

9. Two distinct lines in a plane that have a common point are called intersectingparallel lines.

10. Perpendicular Lines: Two intersecting lines are perpendicular if they form a ° angle.

11. If two lines in a plane do not intersect, they are called lines.

12. Two parallel lines do not have any points.