1. 6.1 Perpendicular and Angle Bisectors
Period 1/2 – Did Geogebra for Angle and Perpendicular Bisector

2. Geogebra Warm-up
With geogebra, try to create a diagram of two triangles sharing a side where the longest side out of the five sides is not opposite the largest angle.

3. Open a new Geogebra File
Construct a line segment AB.
Construct a perpendicular bisector (4th from left, 3rd down) through that segment.
Place a point C on the perpendicular bisector.
Construct segments AC and BC.
Two finger click on AC, click on object properties, click show label: value. Repeat for BC.
Move point C with the arrow tool and make a conjecture about a point on a perpendicular bisector.

4. Perpendicular Bisector Theorem
If a point lies on the perpendicular bisector of a segment, then it is equidistant from the endpoints of the segment. Proof The converse is also true.

5. Perpendicular Bisector Converse
If a point is equidistant from the endpoints of a segment, then it lies on the perpendicular bisector of the segment.

6. Perpendicular Bisector of a Triangle
A line that divides one side of a triangle into two congruent parts and is perpendicular to that side

7. If there’s a point on the Perpendicular Bisector, then it is equidistant to the endpoints of the segment.

8. Open a new Geogebra File
Construct:
an angle (8th from left, top choice).
rays (3rd from left, 4th down) as the sides of the angles.
an angle bisector(4th from left, 4th down)
two perpendicular lines (4th from left, top choice), each through a side of the angle and through the SAME POINT on the angle bisector.
construct a circle with a center at the “SAME POINT” in the previous step through a point where a perpendicular line intersects with a side of the angle.

9. Angle Bisector of a Triangle
A segment that lies on an angle bisector and that has one endpoint at the vertex and the other on the opposite side of the triangle

10. If there’s a point on the Angle Bisector, then it is equidistant from the sides of the angle.
The converse is also true.

11. Altitude of a Triangle
A perpendicular segment from a vertex to the base or to the line containing the base

12. Median of a Triangle
A line segment connecting a vertex of a triangle to the midpoint of the opposite side

13. Midsegment of a Triangle
A line segment connecting the midpoints of two sides of the triangle

14. Properties of the Midsegment of a Triangle
1 – The midsegment is half the length of the base
2 – The base and the midsegment are parallel

15. Sketch each of the following in a triangle with the proper markings
Perpendicular Bisector
Angle Bisector
Median
Altitude
Midsegment

18. Write the equation of the perpendicular bisector given the endpoints of the segment it bisects.
(-2, 3) and (4, 1)
(-1, -5) and (3, -1)
(12, -5) and (18, 5)