MATH GOALS

☆ANGLES☆

NAME OF ANGLES

• Acute angle- an angle that's less than 90 degrees
• Right angle- an angle that is 90 degress exactly
• Obtuse angle- an angle that's greater than 90 degrees but its less than 180 degress
• Straight angle- an angle that is 180 degrees exactly
• Reflex angle- an angle that is greater than 180 degrees

THESE ARE THE TYPES OF ANGLES

Be careful when you're measuring angles. Make sure you know which angle is being asked for!

POSITIVE AND NEGATIVE ANGLES

WHEN MEASURING FROM A LINE,

• A positive angle goes counter clockwise (opposite direction that clocks go)
• A negative angle goes clockwise

PARTS OF AN ANGLE

Untitled Slide

• The corner point of an angle is called the vertex (pink dot)
• And the two straight sides are called arms (yellow and purple dot)
• The angle is the amount of turn between each arm (orange dot)

HOW TO LABEL ANGLES

THERE ARE TWO MAIN WAYS TO LABEL AN ANGLE

• Give the angle a name, usually a lowercase like a or b, or sometimes a Greek letter like a (alpha) or 0 (theta)
• Or by the three letters on the shape that define the angle with the middle letter being where the angle actually is (its vertex)
• Example angle: 'a' is 'BAC', and angle '0' is 'BCD'.

QUESTIONS

THE ANGLE 89 DEGREES IS:

• A: Acute
• B: Right
• C: Obtuse
• D: Reflex

THE ANSWER IS:

THE ANGLE 234 DEGREES IS:

• A: Acute
• B: Obtuse
• C: Straight
• D: Reflex

THE ANSWER IS:

THE ANGLE 98 DEGREES IS:

• A: Acute
• B: Obtuse
• C: Straight
• D: Reflex

THE ANSWER IS:

• C, since 98 degrees is greater than 90 degrees but less than
• 180 degrees, so it's obtuse

APPS/WEBSITES

• www.mathsisfun.com
• Adobe Ideas
• Haiku Deck
• Sketchbook Pro
• And some of Priscillia's knowledge too

☁︎☁︎Thank you for listening☁︎☁︎