Download Welcome to Algebra 1 - Shope-Math

Honors Geometry 24 Oct 2011
Take papers from your folder and put them in your binder.
Place your binder, HW and text on your desk.
PLEASE BRING COMPASS TOMORROW
Warm up:
What are the measures of
angles a and b?
710
a
b
630
840
1360
FINISHED? Try “Hundreds Puzzle” on page 211
Homework due today
NONE
Homework due Oct 25/26
pg. 208 +: 1- 10, 13, 14, 18, 19, 24
#10 and 24- handout
(#24- give related angle and brief reasons for all)
#13, 14--HINT- color congruent angles
Isosceles Triangle vocabulary, pg. 206
(SKETCH in your vocab section)
Vertex Angle
Legs
Base
Angles
Base
1
2
3
1
2
3
1
2
3
1
1
3
2
2
Name each angle:
Vertex angle or base angle?
3
Investigation 1, page 207
• Each person needs: 1 piece patty paper, a protractor
• PUT your name on your piece of patty paper.
Write all your answers on the patty paper.
• Do steps 1 – 5 with your group
Isosceles Triangle Conjecture:
If a triangle is isosceles, then______?
You have 10 minutes to complete the investigation
is the converse true?
converse = ? Check your notes
Switch the If…. and then…. parts
CONVERSE: If a triangle has two congruent angles,
the it is an isosceles triangle.
Demonstration-- Investigation 2- page 208
we will begin to do constructions with a compass
tomorrow
Chapter 4 Triangles
Term
Triangle Sum
Conjecture
Isosceles
triangle
conjecture
polygon sum
Definition
The sum of the measures of
the angles in every triangle is
1800
If a triangle is isosceles, then
its base angles are congruent
The sum of the measures of
the interior angles of a polygon
is 180(n-2), n = # of sides
IF and ONLY IF
when a conjecture AND its converse
are BOTH TRUE
Converse of
Isosceles
Conjecture
If a triangle has two congruent
angles, then it is an isosceles
triangle.
Example
57 o
30o
93o
84o
48o
48o
640
40 0
550
1240
900
Find the missing angle measures.
Label each angle as base angle or vertex angle
Debrief- EQ
what did you learn today?
What was easy for you? What did you like?
What was difficult? Is there something I could
do to help you?