Search results
Results from the WOW.Com Content Network
The final digit of a triangular number is 0, 1, 3, 5, 6, or 8, and thus such numbers never end in 2, 4, 7, or 9. A final 3 must be preceded by a 0 or 5; a final 8 must be preceded by a 2 or 7. In base 10, the digital root of a nonzero triangular number is always 1, 3, 6, or 9. Hence, every triangular number is either divisible by three or has a ...
The angle bisector theorem is commonly used when the angle bisectors and side lengths are known. It can be used in a calculation or in a proof. An immediate consequence of the theorem is that the angle bisector of the vertex angle of an isosceles triangle will also bisect the opposite side.
An angle bisector of a triangle is a straight line through a vertex that cuts the corresponding angle in half. The three angle bisectors intersect in a single point, the incenter, which is the center of the triangle's incircle. The incircle is the circle that lies inside the triangle and touches all three sides. Its radius is called the inradius.
A general form triangle has six main characteristics (see picture): three linear (side lengths a, b, c) and three angular (α, β, γ). The classical plane trigonometry problem is to specify three of the six characteristics and determine the other three. A triangle can be uniquely determined in this sense when given any of the following: [1] [2]
The second of arc (or arcsecond, or just second) is 1 / 60 of a minute of arc and 1 / 3600 of a degree (n = 1,296,000). It is denoted by a double prime ( ″ ). For example, 3° 7′ 30″ is equal to 3 + 7 / 60 + 30 / 3600 degrees, or 3.125 degrees. The arcsecond is the angle used to measure a parsec: grad: 400: ...
There are exactly twenty-seven straight lines on a smooth cubic surface, [2] which give a basis of the fundamental representation of Lie algebra. [ 3 ] [ 4 ] The unique simple formally real Jordan algebra , the exceptional Jordan algebra of self-adjoint 3 by 3 matrices of quaternions , is 27-dimensional; [ 5 ] its automorphism group is the 52 ...
Twenty-eight is: An abbreviation for such years as 1928 and 2028. The number of Hebrew letters in Genesis 1:1, the first verse of the Bible. The number of wheels on a Lockheed C-5 Galaxy. In the code for international direct dial phone calls, +28 is unassigned. 028 is the ISO 3166-1 numeric three-digit country code for Antigua and Barbuda.
In trigonometry, the law of sines, sine law, sine formula, or sine rule is an equation relating the lengths of the sides of any triangle to the sines of its angles. According to the law, = = =, where a, b, and c are the lengths of the sides of a triangle, and α, β, and γ are the opposite angles (see figure 2), while R is the radius of the triangle's circumcircle.