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.
3.) A *the first one*
4.) C *the last one*
Answer:
B. 
Hope this helped. A brainliest would be very much appreciated. (I need 4 brainliest so I can level up) :)
Its adding the current number by the previous number so the next three would be 21,34,55
The midpoint of the segment is (-15/2, -15/2)
<h3>How to determine the midpoint?</h3>
The complete question is in the attached image
The points are given as:
(-8, -7) and (-7, -8)
The midpoint is calculated as:
(x,y) = 1/2 * (x1 + x2, y1 + y2)
So, we have:
(x,y) = 1/2 * (-8 - 7, -7 - 8)
Evaluate the difference
(x,y) = 1/2 * (-15, -15)
Evaluate the product
(x,y) = (-15/2, -15/2)
Hence, the midpoint of the segment is (-15/2, -15/2)
Read more about midpoints at:
brainly.com/question/4747771
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