More About Angles
A point is in the interior of an angle if it is between points that lie on each side of the angle.
A point is in the exterior of an angle if it is not on the angle or in its interior.
![Image](https://stage.geogebra.org/resource/I4jktnOn/DVI2b3IHhhEVSSMt/material-I4jktnOn.png)
Angle Addition Postulate
If P is in the interior of <RST, then m<RSP+m<PST=m<RST.
![Image](https://stage.geogebra.org/resource/JMDI3VVQ/MKFbpI6jeebekj5J/material-JMDI3VVQ.png)