Download Discovering Geometry Day 21

Discovering Geometry
Day 21
3.4 Constructing Angle Bisectors
o Daily Openers
o Check homework
3.4 Constructing Angle Bisectors
Bisecting an Angle (with Patty Paper)
Step 1: Draw an angle, ABC
Step 2: Fold patty paper so that BC and BA overlap.
Step 3: Unfold patty paper and draw a line on the crease.
Step 4: Measure from the sides of the angle to the bisector.
ANGLE BISECTOR CONJECTURE – If a point is on the bisector of an angle, then it is
equidistant from the sides of the angle.
Bisecting an Angle (with Compass and Straightedge)
Step 1: Draw an angle, RPQ
Step 2: From each intersection point, draw an arc (of any measure) and find their intersection point.
Step 4: Draw a line from the vertex, through that intersection point.
Homework – pages 160–161 #1–16
Daily Openers – 1. Graph: 8 x  9 y  27  0
2. Draw CP and find a point not on the segment that is equidistant from C and P.
3. Simplify: 6 3  2


5 9

4. Simplify without a calculator: (a)
2x 4
8x
(b) 3
2
9
5. Two vertical angles measure 11x – 8˚ and 14x – 23˚. Find the measure of each
angle.