Mathematics (2019) Grade(s): 4

MA19.4.26

Decompose an angle into non-overlapping parts to demonstrate that the angle measure of the whole is the sum of the angle measures of the parts.

Unpacked Content

Knowledge

Students know:
  • Angles are measured in degrees from 0 to 360.
  • Protractor orientation does not affect an angle measurement.

Skills

Students are able to:
  • Decompose an angle into non-overlapping parts and demonstrate that the sum of the angle measure parts is the same as the measure of the whole angle.
  • Use addition and subtraction to find unknown angles on a diagram in real-world or mathematical problems.

Understanding

Students understand that:
  • The rotation of an angle is measured by the number of one-degree angles that exactly cover the rotation of the angle.
  • Angle measurement is additive of the non-overlapping parts of a decomposed angle.

Vocabulary

  • Decompose
  • Angle
  • Non-overlapping
  • Angle measure
  • Sum
  • Diagram
  • Adjacent
  • Compose
  • Degrees
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