
Fact 
Category 
Date 

1 
A number is a triangular number if the sum of one and the product of eight and the number is an odd square number. 
Science > Math 
01/10/17 

2 
An amblygon is another word for a(n) obtuse triangle. 
Science > Math 
11/10/11 

3 
The Mayan number system is in base twenty. 
Science > Math 
12/06/09 

4 
The imaginary unit, commonly referred to as "i", is the square root of negative one. 
Science > Math 
02/06/09 

5 
The base of the duodecimal system is 12. 
Science > Math 
01/31/09 

6 
A Klein bottle is a nonorientable surface with no distinct "inner" and "outer" sides. 
Science > Math 
11/16/08 

7 
Spherical trigonometry, studies triangles on spheres, and is important in astronomy and navigation. 
Science > Math 
11/01/08 

8 
There are general formulas for solving polynomial equations of degree less than 5, using only addition, subtraction, multiplication, division, and root extraction, but no such formula exists for polynomials of degree 5 or higher. 
Science > Math 
10/31/08 

9 
A prime number is a number (other than the number 1) that has no numbers that divide evenly into itself besides itself and one. 
Science > Math 
09/25/08 

10 
Unlike in the real numbers and the complex numbers, multiplication in the quaternions is not commutative. 
Science > Math 
09/21/08 

11 
Pi, the mathematical constant, is an irrational number. 
Science > Math 
09/21/08 

12 
Hipparchus invented trigonometry to describe how the planets move. 
Science > Math 
09/21/08 

13 
Goldbach's conjecture states that every even number greater than 2 is the sum of two prime numbers. 
Science > Math 
09/14/08 

14 
Trigonometry is the study of the measurement of triangles. 
Science > Math 
09/12/08 

15 
The base of the quinary system is 5. 
Science > Math 
08/14/08 

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