An integer triangle or integral triangle is a triangle all of whose side lengths are integers. A rational triangle is one whose side lengths are rational...

Heronian triangle (or Heron triangle) is a triangle whose side lengths a, b, and c and area A are all positive integers. Heronian triangles are named...

for any positive integer k. A triangle whose side lengths are a Pythagorean triple is a right triangle and called a Pythagorean triangle. A primitive Pythagorean...

triples are Heronian, meaning they have integer area as well as integer sides. The possible use of the 3 : 4 : 5 triangle in Ancient Egypt, with the supposed...

acute triangle (or acute-angled triangle) is a triangle with three acute angles (less than 90°). An obtuse triangle (or obtuse-angled triangle) is a triangle...

} No two non-congruent triangles share the same set of three internal angle bisector lengths. There exist integer triangles with a rational angle bisector...

A right triangle or right-angled triangle, sometimes called an orthogonal triangle or rectangular triangle, is a triangle in which two sides are perpendicular...

Bernoulli's triangle is an array of partial sums of the binomial coefficients. For any non-negative integer n and for any integer k included between 0...

A triangular number or triangle number counts objects arranged in an equilateral triangle. Triangular numbers are a type of figurate number, other examples...

Heronian triangle Integer triangle Pythagorean triple Eisenstein triple Bermuda Triangle Historic Triangle Lithium Triangle Parliamentary Triangle, Canberra...

Pythagorean triples describing integer-sided right triangles, and there are infinitely many equable right triangles with non-integer sides; however, there are...

of achiral integer partitions of 51 1581 = number of edges in the hexagonal triangle T(31) 1582 = a number such that the integer triangle [A070080(1582)...

The On-Line Encyclopedia of Integer Sequences (OEIS) is an online database of integer sequences. It was created and maintained by Neil Sloane while researching...

are[citation needed] Vertex = <integer>; // v Edge = <integer, integer>; // v0, v1 Triangle <integer,integer,integer>; // v0, v1, v2 VData = <application-specific...

the polygon into triangles with three integer vertices and no other integer points. One can then prove that each subdivided triangle has area exactly...

A Brahmagupta triangle is a triangle whose side lengths are consecutive positive integers and area is a positive integer. The triangle whose side lengths...

once observed that the first five rows of Pascal's triangle, when read as the digits of an integer, are the corresponding powers of eleven. He claimed...

set of integers which are the lengths of the sides of a triangle where one of the angles is 60 or 120 degrees. The relation of such triangles to the Eisenstein...

do not exist two integer-sided right triangles in which the two legs of one triangle are the leg and hypotenuse of the other triangle. More abstractly...

graphs can be interpreted as a discrete analogue of the Sierpiński triangle. For integer number of dimensions d {\displaystyle d} , when doubling a side...

There is a primitive integer-sided automedian triangle that is not generated from a right triangle: namely, the equilateral triangle with sides of unit...

root of any positive integer. Each triangle has a side (labeled "1") that is the chosen unit for measurement. In each right triangle, Pythagoras' theorem...

In a format similar to that of Pascal's triangle, and in the order listed in the On-Line Encyclopedia of Integer Sequences (OEIS), its first few rows are:...

This is a list of notable integer sequences with links to their entries in the On-Line Encyclopedia of Integer Sequences. OEIS core sequences Index to...

A Reuleaux triangle [ʁœlo] is a curved triangle with constant width, the simplest and best known curve of constant width other than the circle. It is formed...

and all of their side lengths are positive integers. Triangles with this property are called Heronian triangles; cyclic quadrilaterals with this property...

divisors (including itself) is also an integer, 54 is an arithmetic number. If the complementary angle of a triangle's corner is 54 degrees, the sine of that...

number preceding a cube. As an early prime number in the series of positive integers, the number seven has symbolic associations in religion, mythology, superstition...

An equilateral triangle may have integer sides with three rational angles as measured in degrees, known for the only acute triangle that is similar to...

formula for the reciprocal area of a triangle", Mathematical Gazette 89 (November 2005), 494. Voles, Roger, "Integer solutions of a − 2 + b − 2 = d − 2...