Download - Tuesday, August 13th
TUESDAY, AUGUST 13TH
Identify each shape
1. H is between I and J.JI = 25 and IH = 13. Find HJ. _____ 2. Find each measurement
HOMEWORK ANSWERS Please ask if you have
questions!
ANGLE EXPLORATION
Need: Paper Protractor Lined
sheet of paper
Angle measure Sheet 1 Sheet 2
<ABC
<ABD
<DBC
DISCUSSION7. What did you notice about the measure of <ABC?
8. What was the relationship between measures of <ABC, <ABD, and <DBC?
Always 90˚ m<ABD + m<DBC=m<ABC
PART 1: NAMING ANGLES
An angle is a figure formed by two rays, or sides, with a common endpoint called the vertex (plural: vertices).
You can name an angle several ways: 1. by its vertex2. by a point on each ray and the vertex3. by a number.
The set of all points between the sides of the angle is the interior of an angle. The exterior of an angle is the set of all points outside the angle.
Angle NameR, SRT, TRS, or 1
A surveyor recorded the angles formed by a transit (point A) and three distant points, B, C, and D. Name three of the angles.
Possible answer:
BAC
CAD
BAD
Example 1
Write the different ways you can name the angles in the diagram.
RTQ, T, STR, 1, 2
Example 2
PART 2: MEASURING ANGLES
The measure of an angle is usually given in degrees. Since there are 360° in a circle, one degree is of a circle. When you use a protractor to measure angles, you are applying the following postulate.
PRACTICE! Draw 2 angles and measure
with your protractor!
Congruent angles are angles that have the same measure. In the diagram, mABC = mDEF, so you can write ABC DEF. This is read as “angle ABC is congruent to angle DEF.” Arc marks are used to show that the two angles are congruent.
Reminder!
PART 3: CONSTRUCTING ANGLES
http://www.youtube.com/watch?v=YphAYfe6J40
EXAMPLE #1- LET’S TRY TOGETHER!
Use your notes from Friday!!!!
“sharp point” = Bullseye end of compass
EXAMPLE #2- YOU TRY!
Use your notes from Friday!!!!
“sharp point” = Bullseye end of compass
PRACTICE A WORKSHEET
Homework