Five-Minute Check (over Lesson 1–3)

NGSSS

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. A

B. B

C. C

D. D A B C D

0% 0%0%0%

A. 2

B. 4

C. 6

D. 8

Use the number line to find the measure of AC.

Over Lesson 1–3

A. A

B. B

C. C

D. D A B C D

0% 0%0%0%

A. 3

B. 5

C. 7

D. 9

Use the number line to find the measure of DE.

Over Lesson 1–3

A. A

B. B

C. C

D. D A B C D

0% 0%0%0%

A. D

B. E

C. F

D. H

Use the number line to find the midpoint of EG.

Over Lesson 1–3

A. A

B. B

C. C

D. D A B C D

0% 0%0%0%

A. 12

B. 10

C. 5

D. 1

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

Over Lesson 1–3

A. A

B. B

C. C

D. D A B C D

0% 0%0%0%

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. A

B. B

C. C

D. D A B C D

0% 0%0%0%

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?

MA.912.G.1.2 Construct congruent segments and angles, angle bisectors, and parallel and perpendicular lines using a straight edge and compass or a drawing program, explaining and justifying the process used.

MA.912.G.8.4 Make conjectures with justifications about geometric ideas. Distinguish between information that supports a conjecture and the proof of a conjecture.

You measured line segments. (Lesson 1–2)

• 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. B

C. C

D. D A B C D

0% 0%0%0%

A.

A.

B.

C.

D.

A. A

B. B

C. C

D. D A B C D

0% 0%0%0%

B.

A.

B.

C.

D. none of these

A.

B.

C.

D.

A. A

B. B

C. C

D. D A B C D

0% 0%0%0%

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. A

B. B

C. C

D. D A B C D

0% 0%0%0%

A. 30°, acute

B. 30°, obtuse

C. 150°, acute

D. 150°, obtuse

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

A. A

B. B

C. C

D. D A B C D

0% 0%0%0%

A. 60°, acute

B. 90°, acute

C. 90°, right

D. 90°, obtuse

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

A. A

B. B

C. C

D. D A B C D

0% 0%0%0%

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. A

B. B

C. C

D. D A B C D

0% 0%0%0%

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.