Supplementary — Grade 7 Accelerated, what it means and where it is taught
Two angles summing to 90° / to 180°.
Taught in Grade 7 Accelerated.
Where it is taught
Practise this idea
5 questions in the course bank use Supplementary, in Geometric Construction, Angle Relationships, Quadrilaterals & Polygon Properties, Circle Angles, Arcs & Chords.
Problem 1
Find the supplement of 52°.
Worked answer
128
180 - 52 = 128°
Problem 2
Two parallel lines are cut by a transversal. One angle is 73°. Find the co-interior angle on the same side.
Worked answer
107
180 - 73 = 107°
Problem 3
Which pair of angles is not necessarily equal when two parallel lines are cut by a transversal?
- Co-interior angles
- Corresponding angles
- Alternate interior angles
- Vertical angles
Worked answer
Co-interior angles
Co-interior angles are supplementary, not equal
They are only equal in the special case of 90° each
Problem 4
In parallelogram ABCD, m∠ A = 70°. Find m∠ B.
Worked answer
110
180 - 70 = 110°
Opposite angles would be 70°.
Problem 5
In a cyclic quadrilateral one angle is 105°. Find the opposite angle.
Worked answer
75
180 - 105 = 75°