CK12 - Geometry

However, and are not adjacentsincethey overlap(i.e. they sharecommonpointsin the
interiorof the angle).

Now we are readyto talk aboutlinearpairs.Alinearpairis two anglesthat are adjacentand whosenon-

commonsidesform a straightline. In the diagrambelow, and are a linearpair. Note

that is a line.

Linearpairsare so importantin geometrythat they havetheir own postulate.

LinearPair Postulate:If two anglesare a linearpair, then they are supplementary.

Example 5

The two anglesbelowform a linearpair. Whatis the valueof eachangle?

If you add the two angles,the sum will be 180º.So, you can set up an algebraicequationwith the values
presented.

The best way to solvethis problemis to solvethe equationabovefor. Then,you mustplug the value

for backinto the originalexpressionsto find the valueof eachangle.