Thread: Questions about triangles and lines

My first question, can a triangle have three angles, 0-180-0, and appear as a line segment with a point in the middle having no altitude?

Also, can a single dot on a piece of paper represent an infinite straight line in aspect to the dot being 3-d, extending through the paper?

Originally Posted by kellyfromwadsworth

My first question, can a triangle have three angles, 0-180-0, and appear as a line segment with a point in the middle having no altitude?

Also, can a single dot on a piece of paper represent an infinite straight line in aspect to the dot being 3-d, extending through the paper?

up to me you are right in both
but if the angles are allowed to be in your triangle definition.

Originally Posted by kellyfromwadsworth

My first question, can a triangle have three angles, 0-180-0, and appear as a line segment with a point in the middle having no altitude?

Also, can a single dot on a piece of paper represent an infinite straight line in aspect to the dot being 3-d, extending through the paper?

Deriving from both, such dot can also be a triangle.

Originally Posted by kellyfromwadsworth

My first question, can a triangle have three angles, 0-180-0, and appear as a line segment with a point in the middle having no altitude?

Also, can a single dot on a piece of paper represent an infinite straight line in aspect to the dot being 3-d, extending through the paper?

There are certain "undefined terms" in geometry. A point and a line are two of them. They can only be described. A point has no dimensions. It simply represents "location". A line has only length. Abstract, at best. That's why we call them undefined.

A triangle is defined as 3 segments connecting 3 non-collinear points. So a straight line fails that definition.