Select the correct name for this object. Is it a line, a ray, a line segment, an angle, or a point?
The object that we need to look at in this question is this one. In everyday life, we might describe this simply as a line, but in maths there are special definitions for some of these words. Let’s remind ourselves what they are, as we try to find the correct name for this object.
The proper definition of a line in maths is a line that extends in both directions without end. So, if we were to expect this object to be a line, we’d want to see arrowheads at the end of each end. This shows that the line continues in both directions. Although we might naturally call it a line, the correct mathematical term is not a line. There’s a better mathematical term we could be using.
What about a ray? Well, a ray in maths is part of a line that has a definite start point but continues on and on in one direction. It has a start point, but no endpoint. And there are no arrowheads in the object that we’re looking at, so we know that this isn’t a ray.
A line segment is part of a line that has a definite start point and end point, doesn’t continue going in both directions. Now, although there are no little circles at either end of the object that we can see in the question, there is definitely a start point and an endpoint. There are no arrowheads to show that the line continues. And so, we know the correct name for the object is a line segment.
We know that an angle is a way of measuring the amount of turn between two lines around a given point. It’s not an angle that we can see. And a point is an exact location. It doesn’t have length or width; it only has position. Of course, the object doesn’t show one point. The object we can see has a definite start point and a definite end point. It doesn’t continue past these points. The correct name for the object is a line segment.