Which of the following is another name for $\angle ABC$?

Which of the following rays are the arms of $\angle BOA$?

A triangle has _____ elements.

In a $△ABC$, the side opposite to $\angle A$ is _____.

In a $△PQR$, the vertex opposite to side $QR$ is _____.

The vertices of a triangle lie on a straight line.

The triangular region includes the vertices of a triangle.

Every triangle has three medians.

The altitude of a triangle drawn from a vertex to the opposite side, bisects the side.