This document covers the basics of lines and angles for 4th graders, defining straight lines, rays, and segments, and explaining parallel, intersecting, and perpendicular lines. It also introduces the concept of angles, their measurement using a protractor, and the relationships between different types of angles. Practical instructions for drawing and measuring angles are provided to aid understanding.

1. Maths4th
grade- Unit 3
LINES
And
ANGLESby MariaAdrover
CEIPCALONGE

2. STRAIGHT LINE
A straight line is a line that does not curve.
A line extends in both directions without end (infinitely)

3. RAY
A ray is a line with a start but without an end.
The point that starts a half-line is called origin.

4. SEGMENT LINE
A line segment is the part of a line connecting
two points.
It has definite end points.

5. PARALLEL LINES
Two lines are parallel if they never meet. They are
always the same distance apart

6. INTERSECTING LINES
Two lines are intersecting if they meet in a point and
form 4 angles.

7. PERPENDICULAR LINES
If the lines make 4 right angles (90º) when they
meet in a point, then they are perpendiculars.

8. ANGLES: Parts and definition
The amount of turn between two straight lines that have a
common end point (the vertex).

9. TYPES OF ANGLES

10. Using the SET SQUARE

11. THE PROTRACTOR
The protractor help us to measure angles.
The angles are measured using degrees (º)

12. GRADING A ANGLE
Set the protractor so that:
– The vertex of the angle match the protractor centre.
– One angle arm should match the base line.
– Read the score, this is the angle measure.
If the arms of the angles are too short...
Make them longer using a ruler and a pencil

13. DRAWING AN ANGLE

14. RELATION BETWEEN ANGLES
● CONSECUTIVE: They have the vertex and one arm in common.
● ADJACENT: They have the vertex and one arm in common and
they form a straight angle.
● INVERSE: They have the vertex and the arms in common. They are
two intersecting lines.