Five-Minute Check (over Lesson 1–3)

CCSS

Then/Now

New Vocabulary

Example 1:Real-World Example: Angles and Their Parts

Key Concept: Classify Angles

Example 2:Measure and Classify Angles

Example 3:Measure and Classify Angles

Over Lesson 1–3

A. 2

B. 4

C. 6

D. 8

Use the number line to find the measure of AC.

Over Lesson 1–3

A. 3

B. 5

C. 7

D. 9

Use the number line to find the measure of DE.

Over Lesson 1–3

A. D

B. E

C. F

D. H

Use the number line to find the midpoint of EG.

Over Lesson 1–3

A. 12

B. 10

C. 5

D. 1

Find the distance between P(–2, 5) and Q(4, –3).

Over Lesson 1–3

A. (–8, 20)

B. (–4, 15)

C. (–2, –5)

D. (2, 20)

Find the coordinates of R if M(–4, 5) is the midpoint of RS and S has coordinates (0, –10).

Over Lesson 1–3

A. Location A, 10 units

B. Location A, 12.5 units

C. Location B, 10 units

D. Location B, 12.5 units

A boat located at (4, 1) can dock at two locations. Location A is at (–2, 9) and Location B is at (9, –11). Which location is closest? How many units away is the closest dock?

Content Standards

G.CO.1 Know precise definitions of angle, circle, perpendicular line, parallel line, and line segment, based on the undefined notions of point, line, distance along a line, and distance around a circular arc.

G.CO.12 Make formal geometric constructions with a variety of tools and methods (compass and straightedge, string, reflective devices, paper folding, dynamic geometric software, etc.).

Mathematical Practices

5 Use appropriate tools strategically.

6 Attend to precision.

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

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

A.

B.

C.

D.

C. Which of the following is another name for 3?

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.

A. 60°, acute

B. 90°, acute

C. 90°, right

D. 90°, obtuse

B. Measure CZE and classify it as right, acute, or obtuse.

A. 30°, acute

B. 30°, obtuse

C. 150°, acute

D. 150°, obtuse

C. Measure DZX 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.