10
36 is a triangular number, Square number and also a Consecutive number.
1, the first triangular number, is also a square.
The number 4
There are an many triangular numbers that are also square numbers. Simply put, the sum of two consecutive triangular number equals a square number. Examples include 1 and 36.
A square number that is also a triangular number is 36. Triangular numbers are generated by the formula ( T_n = \frac{n(n + 1)}{2} ), and for ( n = 8 ), ( T_8 = 36 ). Meanwhile, 36 is also a perfect square, as it equals ( 6^2 ). Thus, 36 is the smallest number that fits both definitions.
36 is the only square number that is also a triangular number between 20 and 40.
1,2,4,5,10
Because 3 is a factor of 9. Any number that has a composite number as a factor will also have that number's factors as factors.
That's a prime factor.
The greatest common factor is also one of the two numbers being factored when that number is a factor of the other one.
1 and 6
A triangular pyramid, also known as a tetrahedron, has one circular base. However, it actually has four triangular faces, with three of them meeting at each vertex. The base is not circular; it is triangular, while the other three faces are also triangular. Therefore, a triangular pyramid has no circular bases.