In this Grade 7 lesson from Big Ideas Math, Course 2, students learn to classify pairs of angles as complementary (summing to 90°) or supplementary (summing to 180°). Students also practice finding unknown angle measures by setting up and solving equations using these angle relationships. The lesson aligns with Florida standard MAFS.7.G.2.5 within the Chapter 7 unit on Constructions and Scale Drawings.
Section 1
Definitions of Complementary and Supplementary Angles
If the sum of the measures of two angles is 180°, then the angles are supplementary.
If the sum of the measures of two angles is 90°, then the angles are complementary.
Section 2
Finding Unknown Angle Measures
To find unknown angle measures in complementary and supplementary pairs:
Set up an equation using the given information and solve for the unknown variable.
Expand to review the lesson summary and core properties.
Section 1
Definitions of Complementary and Supplementary Angles
If the sum of the measures of two angles is 180°, then the angles are supplementary.
If the sum of the measures of two angles is 90°, then the angles are complementary.
Section 2
Finding Unknown Angle Measures
To find unknown angle measures in complementary and supplementary pairs:
Set up an equation using the given information and solve for the unknown variable.