Unit 4: Topic B Lesson

Multiple Choice

Which of the following tools is commonly used to measure angles in degrees?

• Protractor

• Ruler

• Compass

• Thermometer

Open Ended

Why is it important to understand how to measure angles and determine how much of a circle an angle covers?

Open Ended

Look at four diagrams: - Two rays sharing a vertex, forming a small angle. - Two rays sharing a vertex, forming a large angle. - Two rays forming a straight line. - Two rays not sharing a vertex. Signal your choice and explain your reasoning. What makes one diagram different from the others?

Multiple Choice

According to the definition provided, what is required for two rays to form an angle?

• They must be parallel

• They must share a common endpoint

• They must be perpendicular

• They must form a straight line

Multiple Choice

Which of the following statements best describes how we measure how open an angle is?

• By using centimeters

• By using degrees

• By using radians

• By using inches

Open Ended

How does the concept of measuring angles in degrees relate to dividing a circle into equal parts?

Open Ended

How does the fraction of a circle’s circumference between two rays relate to the angle’s measure in degrees?

Open Ended

What does it mean when an angle measures 180 degrees or 90 degrees? What do these angles look like?

Multiple Choice

Which of the following are correct ways to find the degree measure of an angle that cuts out a fraction of a circle?

• Multiply the fraction by 360

• Divide 360 by the fraction

• Multiply the fraction by the radius

• Multiply the fraction by the diameter

Multiple Choice

A circle has a center point O. Ray OA points to the right edge of the circle. Ray OB points straight up to the top edge. What fraction of the circle’s circumference is between rays OA and OB?

• 1/4

• 1/2

• 1/8

• 1/6

Multiple Choice

An angle has its vertex at the center of a circle. Its rays “cut out” 1 / 6 of the circle’s circumference. What is the measure of this angle in degrees?

• 60

• 30

• 90

• 45

Open Ended

Explain what you notice about the shape of the angle formed when the arc between two rays from the center of a circle is half the circle.

Multiple Choice

What is the measure of the angle formed by two rays from the center of a circle, where the arc between them is half the circle?

• 180 degrees

• 90 degrees

• 120 degrees

• 360 degrees

Multiple Choice

Which of the following best describes an arc in a circle?

• The part of a circle’s edge between two points, often 'cut out' by the rays of an angle.

• The center point of a circle.

• A straight line passing through the circle.

• The total circumference of the circle.

Multiple Choice

If an angle 'cuts out' 1/10 of a circle, what is its measure in degrees?

• 36 degrees

• 10 degrees

• 90 degrees

• 180 degrees

Multiple Choice

By the end of this lesson, what should you be able to figure out about angles and circles?

• How to measure angles using degrees and determine how much of a circle an angle covers

• How to draw circles perfectly

• How to find the area of a circle

• How to convert degrees to radians

Open Ended

What is one way you can use degrees to measure angles in a circle?