# What are triangle numbers?

Triangle numbers are a series of sums of the first n numbers. Thus T1 = 1 T2 = 1+2 = 3 T3 = 1+2+3 = 6 T4 = 1+2+3+4 = 10 However, rather than ading up a whole lot of numbers, …it sis easy to prove that Tn = n*(n+1)/2

# What are all the prime numbers up to 21?

2, 3, 5, 7, 11, 13, 17, and 19.

# What are the triangle numbers up to 50?

3,6,10,15,21,28,36,45,55

# What numbers make up the number 21?

20 and 1

# What numbers add up to 21 that have 1 digit?

1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1 is one example.

# What is the fewest number of triangles that make up a trapezoid?

The fewest number of triangles that make up a trapezoid are two isosceles triangles.

# How many degrees does a triangle add up to with only 1 number?

you would do that number plus any letter. than after you woul subtract say 30 and 30+n=180-30 and thats your answer.

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# What are 3 prime numbers that add up to 21?

3, 5, 13 is one possible triplet.

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In Science

# Which numbers can make up a perimeter 10 for a triangle?

You can choose any three numbers that total 10, but the sum of any two of those numbers must be greater than the third number. For example, Isosceles triangles : 3,3,4 : 4,4,2… Equilateral triangle : 3â…“,3â…“, 3â…“ Scalene triangle : 2, 3Â˝, 4Â˝

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# How can numbers 1-9 add up to 15 on each side of the triangle?

The numbers 1-9 sum to 45. If they are to be sum to 15 on each of three sides of a triangle, no number can be counted more than once (15*3 = 45). That is, there are no numbe…rs at any of the vertices. Then there are several possible options: 1, 5, 9 along one side, 2, 6, 7 along the second 3, 4, 8 along the third. So, if x marks the vertices . . . . .x . . . .1 . 2 . . .5 . . . 6 . . 9 . . . . . 7 . x . 3 4 8 . x

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# What two numbers add up to 21 and multiply to 90?

6 and 15

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In Uncategorized

# Three numbers in GP sum up to 21. Their product is 216. Find the numbers?

3 + 6 + 12 = 21 3 x 6 x 12 = 216