An isosceles triangle is a specific type of triangle where only two of the side lengths and two of the internal angles are equal. There are also other types of triangles like equilateral triangles and scalene triangles.
Know MoreA triangle is a basic polygon shape with three sides. The sides must all be straight and form a closed loop. The internal angles of a triangle always add up to 180 degrees.
It is possible for all three sides of a triangle to be the same length. If they are, the angles will also be the same, with a size of 60 degrees. This is a special type of triangle called an equilateral triangle.
In addition to isosceles and equilateral triangles, there are also triangles where none of the sides or angles are the same size. These are called scalene triangles.
Triangles can also be classified according to the size of their angles. An acute triangle is one where all angles are less than 90 degrees. If a triangle has one angle that is exactly 90 degrees, it is called a right triangle, named after the right angle it contains. Finally, if a triangle has an angle over 90 degrees, it is classified as an obtuse triangle.
Learn more in ShapesThe Penrose triangle, also known as the Penrose tribar, is an impossible object, which is a type of optical illusion that tricks the mind into interpreting a two-dimensional object as a three-dimensional object. It was first created in 1934 by the Swedish artist Oscar Reutersvard, but it was popularized in the 1950s by Lionel and Roger Penrose.
Full Answer >The area of a triangle is found by multiplying one-half times its base times its height. According to Wolfram Mathworld, Beyer and Baker there are 110 formulas for the area of a triangle.
Full Answer >The perimeter of a triangle is the total distance around its three outer sides. If a triangle has side lengths equal to D, E and F, then its perimeter is the addition of D, E and F.
Full Answer >A triangle can never have any parallel lines because there must be three angles that add up to 180 degrees, which makes it impossible for the three sides to avoid intersecting. A parallel line can never intersect with another, and triangles must always have intersecting sides.
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