MathematicsClass 7Lines and Angles
Adjacent and Linear Pair Angles
Recognizing adjacent angles and special linear pairs that form a straight line.
Class 7 · MathematicsCBSE & ICSE SOF IMO
Definition
Adjacent angles share a common vertex and a common arm, but their interiors do not overlap. A linear pair is a special pair of adjacent angles whose non-common arms form a straight line, meaning they are supplementary.
Key formula
Linear Pair: Angle 1 + Angle 2 = 180 degrees
Worked examples
1
Two angles sharing a common ray dividing a larger angle are adjacent angles.
2
Two adjacent angles on a straight line measuring 110 degrees and 70 degrees form a linear pair.
3
Angles forming a straight line where one angle is 60 degrees means the other is 120 degrees.
Common mistakes
- • Assuming any two angles that add up to 180 degrees form a linear pair, even if they are not adjacent.
- • Thinking adjacent angles cannot overlap at all, rather than recognizing they simply cannot share interior points.