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7th Grade Math / Lesson 3: Angle Relations

What will we be learning in this lesson?

  • In this lesson, you will learn more about angles and their measures.
Vocabulary words are found in this purple color throughout the lesson. Remember to put these in your notebook.


  • Congruent angles are angles that have the same measure.

  • Vertical angles have rays going in opposite directions from the same vertex.

    In this drawing, angles A and D are vertical angles. Another pair of vertical angles is angles B and C. Vertical angles are always congruent.

  • Adjacent angles share a vertex and a side. In the drawing above, angles A and B are adjacent. Another pair of adjacent angles is angles A and C. Another pair of adjacent angles is angles B and D.
    Are there any more pairs of adjacent angles in the drawing?


  • Complementary angles are two angles that add up to 90 degrees. (Which is a right angle.)

  • Supplementary angles are two angles that add up to 180 degrees. (Which is a straight angle.)

    Be sure to go back to lesson 1 if you do not remember the correct notation for naming angles.

  • Can you identify an angle and its measure?
  • Go back to the classroom to get to your homework and any other items you need to attend to.