You must complete Plane Shapes to unlock this Lesson.
ANGLES
CONTENT
- Naming of Angles (acute, right, complementary, obtuse, straight, supplementary reflex angles and angle at a point)
- Units and Measurement of Angles
- Angles between Lines (vertically opposite, angle on a straight line and angle at a point)
- Angles between Parallel Lines (adjacent, alternate and corresponding angles)
Names of Angles
As the angle increases, the name changes:
Supplementary Angles
Two angles are supplementary when they add up to \(180\) degrees. They don’t have to be next to each other, just so long as the total is \(180\) degrees.
Examples:
\(60^o\) and \(120^o\) are supplementary angles.
\(93^o\) and \(87^o\) are supplementary angles.
Complementary Angles
Two angles are complementary when they add up to \(90\) degrees (a right angle).
They don’t have to be next to each other, just so long as the total is \(90\) degrees.
Examples:
\(60^o\) and \(30^o\) are complementary angles.
\(5^o\) and \(85^o\) are complementary angles.
CLASS ACTIVITY
- Find the angle that is complementary to (a) \(75^o\) (b) \(105^o\).
You are viewing an excerpt of this lesson. Subscribing to the subject will give you access to the following:
- NEW: Download the entire term's content in MS Word document format (1-year plan only)
- The complete lesson note and evaluation questions for this topic
- The complete lessons for the subject and class (First Term, Second Term & Third Term)
- Media-rich, interactive and gamified content
- End-of-lesson objective questions with detailed explanations to force mastery of content
- Simulated termly preparatory examination questions
- Discussion boards on all lessons and subjects
- Guaranteed learning
ClassHall Instructor
Ezimeruwe Oghenekaro
Halima Ahmadu
Sadiq Barau