Unit 1 - Constructions
Congruent Segments
Given:
Construct: A segment congruent to
General notes: If you can use the undo/redo arrows at the top right of the constructions window. If things get really messy and you need to start over, press your browser's refresh button.
Procedure:
1. Use the line tool to draw line CD some space below . They should not intersect.
2. Use the Point On Object tool to plot point E on line CD.
3. Use the compass tool. To set the radius as length AB:
click point A.
Click point B.
4. Click point E (to center the compass at point E).
5. Mark the compass's point of intersection with the Intersect tool. It will label this point F.
6. You have constructed .
Remember:
- Given info: red
- Arcs utilized in construction: green
- The final construction: blue
Congruent Angles
Given:
Construct: An angle congruent to
General notes: To start over, press your browser's refresh button.
Procedure:
1. Select the Ray tool. Draw ray DE such that point D is in the lower left of the construction window, and point E is in the lower right.
2. Use the Point On an Object tool and place point F on the shorter ray of .
3. Select the circle tool.
4. Click point B as the center.
5. Click point F as your radius.
6. Select the Intersect tool and mark point G where your circle intersects the longer side of .
7. Click point D as the center where you place the congruent circle.
8. Select the Intersect tool and mark point H where your circle intersects ray DE.
9. Select the Compass tool.
10. Anchor your compass at F. Open its radius to G. Translate this circle to be centered at H.
11. Use the intersect tool to mark where circle D intersects with circle H.
12. Use the ray tool to create ray DI.
Remember:
- Given info: red
- Arcs utilized in construction: green
- The final construction: blue
Angle Bisector
Given:
Construct: A ray bisecting
General notes:
- Draw an arc = use compass
- With the same radius = use compass
- If lines or curves intersect = use intersect tool to label that point
Procedure:
Using what you learned about GeoGebra from the examples above and the constructions yesterday, bisect the angle below.
Remember:
- Given info: red
- Arcs utilized in construction: green
- The final construction: blue
Perpendicular Bisector
Given:
Construct: The perpendicular bisector of
General notes:
- Draw an arc = use compass
- With the same radius = use compass
- If lines or curves intersect = use intersect tool to label that point
Procedure:
Using what you learned about GeoGebra from the examples above and the constructions yesterday, create a perpendicular bisector to the segment AB below.
Remember:
- Given info: red
- Arcs utilized in construction: green
- The final construction: blue