In the diagram(please see attachment), the exterior angles of triangle ABC are <FAC, <ACD, <ECB, <CBI, <HBA and <BAG. What about the angles <, <DCE, <HBI, are they not exterior?

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- July 16th 2013, 02:51 PMhisajeshExterior angles
In the diagram(please see attachment), the exterior angles of triangle ABC are <FAC, <ACD, <ECB, <CBI, <HBA and <BAG. What about the angles <, <DCE, <HBI, are they not exterior?

- July 16th 2013, 03:26 PMPlatoRe: Exterior angles
Look at this webpage.

Note that has a side of , , as a subset.

But has no side of , as a subset. - July 16th 2013, 03:28 PMHallsofIvyRe: Exterior angles
The

**definition**of "exterior angle". is "

Exterior Angles of Polygons

"The Exterior Angle is the angle between any side of a shape,

and a line extended from the next side."

http://en.wikipedia.org/wiki/Internal_and_external

"an exterior angle (or external angle) is an angle formed by one side of a simple, closed polygon and a line extended from an adjacent side."

What you have is two "lines extended from adjacent sides". - July 16th 2013, 06:04 PMPlatoRe: Exterior angles
This strictly a post script to both of the replies posted.

I have no idea what level we are actually dealing with.

I would like to nail a definition for an exterior angle of a convex polygon.

This is due to R.L.Moore by way of his student Ed Moise in__ELEMENTRY GEOMETY: from an advanced standpoint__.

We need to know what it means that.*two angles form a linear pair*

We say that is an exterior angle if and only if that angle forms a linear pair with an interior of the polygon with vertex