Question

1.a number preceded by triangle 2.the difference between maximum heights and minimum heights in area of steep slope 3.the accurate height in areas of steepslope (use the terms in contours /one word answer)​

Answer 1

Answer:

Triangular Number Sequence. This is the Triangular Number Sequence: 1, 3, 6, 10, 15, 21, 28, 36 and 45 .