| --- |
| source: ncert |
| topic: geometry |
| class_level: class_6 |
| chapter: ch14 |
| difficulty: beginner |
| --- |
| |
| Class 6 | Ch14: Practical Geometry |
| Tools: Ruler, Compass, Protractor, Divider, Set squares. |
| Perpendicular bisector of AB: open compass>half AB, arcs from A and B, intersect at P and Q, join PQ. |
| Angle bisector of angle AOB: arc from O cuts both rays at P,Q. Equal arcs from P,Q intersect at R. OR bisects angle. |
| Standard angles with compass: 60°(equilateral triangle), 90°(perp bisector method), 30°(bisect 60°), 45°(bisect 90°), 75°=60°+15°. |
| Compass must not slip while drawing arc. Centre of protractor EXACTLY on vertex. |
| Must open compass MORE than half segment for perpendicular bisector to work. |
