3. https://www.youtube.com/watch?v=NVuMULQjb3o
https://www.youtube.com/watch?v=UgfSwlqi4Qg
https://www.youtube.com/watch?v=_n3KZR1DSEo
There are 5 types of angles.
Right Angle
Straight Angle
Acute Angle
Obtuse Angle
Reflex Angle
Angles are measured in something called degrees. You measure from
one ray/arm to another. You use a protractor to measure the degrees
in an angle.
Identifying angles (Page 126-129)
7. Right angles always equal EXACTLY 90 degrees. Usually
identified by a square on the vertex.
Straight angles always equal EXACTLY 180 degrees.
Obtuse angles (I like to think obese to help me
remember,) are bigger than 90 degrees but less than 180
degrees.
Acute angles (I like to think awe cute cause they’re little,)
are less than 90 degrees but bigger than 0 degrees.
Reflex angles are bigger that 180 degrees (the opposite
side of all right, acute and obtuse angles are reflex
Identifying angles (Page 126-129)
12. Step 1: Decide whether your angle is acute, obtuse, straight, right,
or reflex
Step 2: Line the vertex of the angle on the center circle/cross
section of you protractor
Step 3: Pick an ray/arm to be your base line, line your base line
with the zero line on the protractor
Step 4: Follow the other ray/arm to see where it measures on the
protractor, but be careful there will be two numbers and you
need pick the correct one by remembering what type of angle you
labeled in step 1. If you decided it was an acute angle then the
measurement needs to be less than 90 degrees.
Measuring Angles (Page 130-138)
16. https://www.youtube.com/watch?v=6oiDPXle97c
You’ll need a pencil, a protractor, and a ruler
Step one: Draw a base line
Step 2: Draw a vertex
Step 3: Place your protractor on your vertex and base line
Step 4: Put a dot on the measurement you are drawing. (Remember
what type of angle is it? Acute, obtuse, right, straight?)
Step 5: Connect your dot with the vertex
Step 6: Double check your work
Drawing Angles (Page 139-142)
17. What happens when a question asks you to measure or draw a
reflex angle?
It’s easier then you think. If an angle was to rotate a full circle
that would equal 360 degrees.
If you were asked to draw a 200 degree angle, that’s 200 degrees
of 360.
So you go 360-200= 160
Draw the obtuse angle of 160 and then the exterior angle of that
is the reflex angle 200 degrees.
Let me show you on the board.
Drawing Angles (Page 139-142)
19. https://www.youtube.com/watch?v=DGKwdHMiqCg
https://www.youtube.com/watch?v=_7FwqgcCSA0
Complimentary Angles: The easiest what to think of this is a right
angle that has been split in two. Complimentary angles always
total 90 degrees.
Supplementary Angles: The easiest way to think of this is a
straight angle that has been split in two. Supplementary angles
always total 180 degrees.
Supplementary and Complementary
Angles (Page 146-149)
24. https://www.youtube.com/watch?v=YnDeYhBoCzs
All angles in a triangle total 180 degrees
https://www.youtube.com/watch?v=6ApegKO75d0
All angles in a quadrilateral total 360 degrees
Missing Angles in Triangles and
Quadrilaterals (Page 150-153)
25. Step 1: Add the two given angles together
Step 2: Subtract the answer from step 1 by 180
Step 3: Your answer in step 2 is your missing angle
If it’s an isosceles triangle (two sides and angles are exactly the
same, you’ll know because they’ll be labeled with the same
letter, like X and X) and they only give you the one angle that is
different you can subtract that angle from 180 and divide by 2.
Let’s do a couple examples on the board.
Missing angle in a Triangle
29. Step 1: Add the two given angles together
Step 2: Subtract the answer from step 1 by 360
Step 3: Your answer in step 2 is your missing angle
Sometimes they give you a more complicated question,
like a quadrilateral that also has
complimentary/supplementary angles. Don’t panick, just
break it down. Figure out the
complimentary/supplementary angles and then carry on
with the steps above.
Missing angle in a Quadrilateral
