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Geometry
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Angles –p. 332-335
Triangles –p.342-345
Name: _________________________
Test is on: ______________________
SOL
5.11 The student will measure right, acute, obtuse, and straight angles.
5.12 The student will classify
a) angles as right, acute, obtuse, or straight, and
b) triangles as right, acute, obtuse, equilateral, scalene, or isosceles
*Angles
- an _angle__ is formed by two rays that have the same endpoint.
-a ___vertex_____ is the common endpoint in an angle.
-the ____interior_______ of an angle are the points between two rays of an angle.
-the ____exterior_______ of an angle are the points outside two rays of an angle.
-angles are measured in _______degrees______
- a _____protractor______ is a tool used for measuring angles.
*Types of Angles
-a ___right______ angle has a measure of 90˚.
-an ___acute______ angle has a measure between 0˚ and 90˚.
-an _____obtuse_____ angle has a measure between 90˚ and 180˚.
-a ___straight______ angle has a measure of 180˚.
*How to Measure Angles
1. Place the crossbar/center of your protractor over the vertex.
2. Line up the 0° line with one side of the angle.
3. Find the point where the other side of the angle intersects the curved edge of the
protractor.
4. Read the number that is written on the protractor at the point of intersection.
*How to Draw an Angle
1. Draw a ray using the straight edge of your protractor.
2. Place the crossbar/center of your protractor on one end of your ray (the vertex).
3.Line up the 0° line with the ray you just drew.
4. Find the degree you want and draw a point.
5. Using the straight edge of your protractor, connect the vertex to the point you drew.
*Triangles
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____equilateral_______ triangle –all sides are the same length
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____isosceles_______ triangle –at least two sides are the same length
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__scalene_______ triangle –no sides are the same length
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__right_______ triangle –has one right angle
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____acute_______ triangle –all three angles are acute
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____obtuse________ triangle –has one obtuse angle
-The interior angles of a triangle always add up to ___180º_____.
60˚
90˚ + 60˚ + x = 180˚
150˚ + x = 180˚
-150˚
-150˚
X = 30˚
Designed by Tara VanPatten