Lesson 1-4 Angle Measure. Ohio Content Standards:

Lesson 1-4Angle Measure

Ohio Content Standards:Ohio Content Standards:

Ohio Content Standards:Ohio Content Standards:

• Formally define geometric figures.

• Recognize and apply angle relationships in situations involving intersecting lines, perpendicular lines and parallel lines.

Vocabulary:Vocabulary:

Vocabulary:Vocabulary:• Degree -Degree -

Vocabulary:Vocabulary:• Degree –Degree –

• A unit of measure used in measuring angles and arcs.

Vocabulary:Vocabulary:• Ray –Ray –

Vocabulary:Vocabulary:• Ray –Ray –

• Part of a line that has one endpoint and extends indefinitely in one direction.

A B

Vocabulary:Vocabulary:• Opposite Opposite

Rays –Rays –

Vocabulary:Vocabulary:• Opposite Opposite

Rays –Rays –• Two rays BA and BC

such that B is between A and C.

B CA

Vocabulary:Vocabulary:• Angle –Angle –

Vocabulary:Vocabulary:• Angle –Angle –

• Formed by two noncollinear rays that have a common endpoint.

B

4A

C

Side AB

Side AC

Vertex A

Vocabulary:Vocabulary:• Sides –Sides –

Vocabulary:Vocabulary:• Sides –Sides –

• The two noncollinear rays that form an angle.

Vocabulary:Vocabulary:• Vertex –Vertex –

Vocabulary:Vocabulary:• Vertex –Vertex –

• The common endpoint of the two noncollinear rays that form an angle.

Vocabulary:Vocabulary:• Interior –Interior –

Vocabulary:Vocabulary:• Interior –Interior –

• A point that lies on the inside of an angle.

D

Point D is in the interior of the angle

Vocabulary:Vocabulary:• Exterior –Exterior –

Vocabulary:Vocabulary:• Exterior –Exterior –

• A point that lies on the outside of an angle.

E

Point E lies in the exterior of the angle

G

F

E

D

BA

65

43

G

F

E

D

BA

65

43

• Name all angles that have B as a vertex.

• Name the sides of 5.

• Write another name for 6.

G

F

E

D

BA

65

43

• Name all angles that have B as a vertex.

• Name the sides of 5.

• Write another name for 6.

G

F

E

D

BA

65

43

• Name all angles that have B as a vertex.

• Name the sides of 5.

• Write another name for 6.

Vocabulary:Vocabulary:

Vocabulary:Vocabulary:• Right Angle –Right Angle –

Vocabulary:Vocabulary:• Right Angle –Right Angle –

• An angle that measures exactly 90°.

Vocabulary:Vocabulary:• Acute Angle –Acute Angle –

Vocabulary:Vocabulary:• Acute Angle –Acute Angle –

• An angle that measures less than 90°.

Vocabulary:Vocabulary:• Obtuse Angle –Obtuse Angle –

Vocabulary:Vocabulary:• Obtuse Angle –Obtuse Angle –

• An angle that measures between 90° and 180°.

Vocabulary:Vocabulary:• Angle Angle

Bisector –Bisector –

Vocabulary:Vocabulary:• Angle Angle

Bisector –Bisector –• A ray that divides an

angle into two congruent angles.

Classify each angle named as right, acute, or obtuse.

YX

W

VU

T

S

Classify each angle named as right, acute, or obtuse.

TYV a)

YX

W

VU

T

S

Classify each angle named as right, acute, or obtuse.

TYV a)

WYT b)YX

W

VU

T

S

Classify each angle named as right, acute, or obtuse.

TYV a)

WYT b)YX

W

VU

T

S

TYU c)

Wall stickers of standard shapes are often used to provide a stimulating environment for a young child’s room. A five-pointed star sticker is shown with vertices labeled. Find

K

J

I

HG

ED

C

B

A

Assignment:

Pgs. 34 - 36 12-36 all, 52-60 all