Lines, rays, segments and angles

Find the rays, draw parallel and perpendicular lines on dotty paper, and compare angles with a right-angle corner.

Guide

This studio is for Years 3 and 4. Children tap dots to draw lines; Undo takes back the last step.

A line segment has two ends, so it can be measured. A ray starts at a point and goes on for ever in one direction. A line goes on for ever both ways. Books show "goes on" with an arrowhead, and so does the board wherever a line or ray runs off the edge.

On dotty paper a parallel line has the same gradient (steepness): if the segment goes 3 across and 1 up, so must the parallel line. A perpendicular line makes a right angle with the segment; it is not always "standing up".

An angle is an amount of turn, not a length. Fold a sheet of paper twice to make a right-angle checker and compare angles with it: smaller is an acute angle, the same is a right angle, bigger is an obtuse angle.