This statement is true.
A pyramidal number tells the number of balls that could be stacked evenly with square bases. If were are looking for the nth pyramidal number, that is a pyramid with a square base that is n by n.
Answer:
In naming a ray, we always begin with the letter of the endpoint (where the ray starts) followed by another point on the ray in the direction it travels. Since the vertex of the angle is the endpoint of each ray and our vertex is , each of our rays must begin with . Only fails to do so.
