12 Components
Big Ideas
Formative Assessment Lesson
End of Unit Assessments
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Big Ideas
Formative Assessment Lesson
End of Unit Assessments
Big Idea:

### Congruent angles have equal angle measure.

1 week

Evidence of Understanding

• describe qualities that make two angles congruent or incongruent
• define an angle using its vertex and rays
• recognize that as an angle measure increases, its arc measure increases
• define all straight angles as having 180° and are therefore all congruent angle measures
• show and describe why an angle whose arc measure is 180° is also a semi-circle
• show and describe why an angle whose arc measure is 360° is also a complete circle
• justify which qualities are mathematically significant or insignificant for determining if two angles are the same
• Example: degree measure vs. color of the angle, length of the rays, thickness, etc.

• construct congruent angles and justify their congruence
• compare methods for determining congruence and describe advantages of each type
• Examples: paper folding, placing angles on the coordinate grid, using patty paper or online software to translate, rotate, or reflect image, etc.
• given an angle, create a congruent angle, and explain why they are congruent
• use notation to signify congruence
• consider and describe implications of human error
• bisect an angle and justify congruence of both parts
• use angle addition to explain that each part is half the degree measure of the whole
• construct congruent right angles using a perpendicular bisector

• perform constructions and analyze the relationships among the segments or angles created
• explore congruent relationships between segments and angles formed by constructing a perpendicular bisector
• describe how two congruent angles are sectors of the same circle, including congruent radii and arc measures

Develop conceptual understanding:

angle, vertex, ray, degree measure, sector of a circle, perpendicular, angle addition, right angle, perpendicular, perpendicular bisector, straight angle

Supporting terms to communicate:

congruent, incongruent, point, line, line segment, length measure, acute, obtuse, circle, arc, radius, equidistant, distance, bisect, midpoint, compass, construction, partition, protractor
Core Resource
A core resource supports multiple days of instruction.
• Matching Angles
The goal of this week is for students to revisit what an angle is and explore what makes two angles congruent using a variety of different tools. Students will also complete a series of constructions that relate to angle congruence.
Resource:
Matching Angles

The goal of this week is for students to revisit what an angle is and explore what makes two angles congruent using a variety of different tools. Students will also complete a series of constructions that relate to angle congruence.

All Resources From:
• Unit 1