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Q: What are the Triangle numbers up to 21?
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Related questions

What arethe first 6 triangle numbers?

1, 3, 6, 10, 15, 21


What is the sixth triangular number?

Triangular numbers are numbers that are formed from the sum 1+2+3+4... The equation for the nth triangle number is (n2+n)/2 In this case, we want the sixth triangle number, so feed this into the equation: (62+6)/2 =(36+6)/2 =42/2 =21 Thus the sixth triangle number is 21.


Can 859 make a triangle?

No 859 is a number, to make a triangle you need to join up lines not numbers.


What is the first ten triangle numbers?

Depending upon the definition used, the first 10 natural numbers are either: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or (first appearing in the 19th century): 0, 1, 2, 3, 4, 5, 6, 7, 8, 9


What six odd numbers add up to 100?

21, 21, 21, 21 , 15, 1


What 4 numbers add up to 21?

25


What is the nth term formula for the triangle numbers 1 3 6 10 15 21?

(n^2+n)/2


What two triangle numbers make thirty eight?

28 and 10 are both triangular numbers and add up to 38


How are the odd numbers arranged in Pascal's Triangle?

how are the odd numbers arranged Pascal's Triangle?


Is 21 a number in the Fibonacci sequence?

Yes, 21 is a number in the Fibonacci sequence. Numbers are usually found by adding up 2 numbers.


What numbers make up the number 21?

20 and 1


What is this triangle 78 42?

78 42 are, as far as I can make out, two numbers. They do not make a triangle.78 42 are, as far as I can make out, two numbers. They do not make a triangle.78 42 are, as far as I can make out, two numbers. They do not make a triangle.78 42 are, as far as I can make out, two numbers. They do not make a triangle.