Bell Ringer – Put in your notebook.

Constructions - Turn to p. 30 ‘Bisect a Segment”

Do Steps 1-3

Use half of a sheet of paper in your notes

Turn in all packets, compass constructions (bisect a segment) progress reports and missing assignment

You measured line segments.

• Measure and classify angles.

• Identify and use congruent angles and the bisector of an angle.

• ray

• opposite rays• angle• side• vertex• interior• exterior

• degree• right angle• acute angle• obtuse angle• angle bisector

• A ray is a part of a line it has one endpoint. The symbol for ray is an arrow in one direction → above the name of the ray.

• An angle is formed by 2 noncollinear rays that have a common endpoint. The rays are the sides of the angles.This common endpoint is called the vertex.

• Naming an angle• When naming an angle use 3 letters, the

vertex must be the second letter.• You can also name an angle using a number

or a single letter.

Angles and Their Parts

A. Name all angles that have B as a vertex.

Answer:

Angles and Their Parts

Answer:

B. Name the sides of 5.

Angles and Their Parts

C.

A.

A.

B.

C.

D.

B.

A.

B.

C.

D. none of these

C. What are other ways to name for 3?

AXB, BXA, NXA, AXN

Could we also name 3 as X?

Measure and Classify Angles

A. Measure TYV and classify it as right, acute, or obtuse.

Answer: mTYV = 90, so TYV is a right angle.

Measure and Classify Angles

Answer: 180 > mWYT > 90, so WYT is an obtuse angle.

Measure and Classify Angles

A. 30°, acute

B. 30°, obtuse

C. 150°, acute

D. 150°, obtuse

A. Measure CZD and classify it as right, acute, or obtuse.

Measure and Classify Angles

INTERIOR DESIGN 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 mGBH and mHCI if GBH HCI, mGBH = 2x + 5, and mHCI = 3x – 10.

Measure and Classify Angles

GBH HCI Given

mGBH = mHCI Definition of congruent angles

2x + 5 = 3x – 10 Substitution

2x + 15 = 3x Add 10 to each side.

15 = x Subtract 2x from each side.

Step 1 Solve for x.

Measure and Classify Angles

Step 2 Use the value of x to find the measure of either angle.

.

Answer: mGBH = 35, mHCI = 35

A. mBHC = 105, mDJE = 105

B. mBHC = 35, mDJE = 35

C. mBHC = 35, mDJE = 105

D. mBHC = 105, mDJE = 35

Find mBHC and mDJE if BHC DJE, mBHC = 4x + 5, and mDJE = 3x + 30.

• Exit Ticket p. 41 5-8

• Class Assignment and HW • p. 41-44 1-6, 9-10, 32, 47, 51, 54, 56, 65,

74-75 • Copy an angle using a compass and

protractor