angle

ANGLE

•A FIGURE FORMED BY TWO NONCOLLINEAR RAYS WITH A COMMON ENDPOINT.

ANGLE•The TWO NONCOLLINEAR RAYS (ray BP & ray BC) are the SIDES of an angle.

ANGLE•The point where the rays intersect is called the VERTEX of an angle.

ANGLE MNEMONIC•S- Sides are 2 non-collinear rays.•E- Endpoint is also called vertex. •R- Rays are the 2 sides.•V- Vertex is the common

endpoint.

AN ANGLE SEPARATES A PLANE INTO 3 PARTS

• INTERIOR ANGLE- point D•EXTERIOR ANGLE – point H•THE ANGLE ITSELF

P, A, W,C●H

●D

EXAMPLES

An angle is named by:An angle is named by:

1.USING 3 POINTS.EXAMPLE:ABC

orCBAPBW or WBP

2. BY THE VERTEX ALONE.

EXAMPLE:

B

An angle is named by:An angle is named by:

3. BY USING A NUMERAL.

EXAMPLE:

11 1

An angle is named by:An angle is named by:

EXERCISESEXERCISES

3

2

1

NAME THE ANGLES USING NAME THE ANGLES USING 3 POINTS3 POINTS

32

1

NAME THE ANGLES USING NAME THE ANGLES USING A NUMERALA NUMERAL

ANOTHER NAME OF ANOTHER NAME OF ANGLE 1.ANGLE 1.

AP

3

2

1

WHAT ARE THE SIDES OF WHAT ARE THE SIDES OF ANGLE 3.ANGLE 3.

B or B or ABWABW

PBC or PBC or ABCABC

Segment Segment AC and AC and ray APray AP

WHAT IS THE COMMON WHAT IS THE COMMON SIDE OF SIDE OF 2 AND 2 AND 3?3?

3

2

1

Segment Segment ACAC

EXAMPLE 5 Name angles

Name the three angles in the diagram.

WXY, or YXW

YXZ, or ZXY

WXZ, or ZXW

You should not name any of these angles X because all three angles have X as their vertex.

Degrees: Measuring AnglesDegrees: Measuring AnglesAngles are measured in Angles are measured in units called units called DEGREESDEGREES and and classified according to their classified according to their measures.measures.

Acute AnglesAcute Anglesan angle measuring an angle measuring between 0 and 90 degreesbetween 0 and 90 degrees

Obtuse AnglesObtuse Anglesan angle measuring an angle measuring between 90 and 180 between 90 and 180 degreesdegrees

Right AnglesRight Anglesan angle measuring exactly an angle measuring exactly 90 degrees.90 degrees.

Obtuse AnglesObtuse Anglesan angle measuring an angle measuring between 90 and 180 between 90 and 180 degreesdegrees

Degrees: Measuring AnglesDegrees: Measuring AnglesWe measure the size of an We measure the size of an angle using a device called angle using a device called the the PROTRACTORPROTRACTOR. .

HOW TO USE A PROTRACTORHOW TO USE A PROTRACTOR

Use a protractor for Use a protractor for exercises 1-2exercises 1-2

Construct an angle with a Construct an angle with a measure of 45 degrees.measure of 45 degrees.

Construct an angle with Construct an angle with measure of 125 degrees. measure of 125 degrees.

QUIZQUIZ1. NAME THE 1. NAME THE

ANGLES USING 3 ANGLES USING 3 POINTS.POINTS.

2. WHAT ARE THE 2. WHAT ARE THE SIDES OF SIDES OF PAR?PAR?

3. WHAT IS THE 3. WHAT IS THE VERTEX OF VERTEX OF DAR?DAR?

D

A

P

R

HOMEWORK

WHAT IS A POLYGON?WHAT ARE THE TYPES OF POLYGON?