Triangles

An acute triangle is a triangle where all three angles are less than 90 degrees.

A scalene triangle is a triangle in which all three sides are of different lengths.

An isosceles triangle is a triangle that has exactly two sides of equal length.

Triangles can be classified by angles as acute (all angles < 90°), right (one angle = 90°), or obtuse (one angle > 90°).

Triangles can be classified by sides as scalene (no equal sides), isosceles (two equal sides), or equilateral (all sides equal).

The sum of the angles in a triangle is always 180 degrees.

To find an unknown angle, subtract the sum of the known angles from 180 degrees.

In a triangle, the largest angle is opposite the longest side, and the smallest angle is opposite the shortest side.

The area of a triangle can be calculated using the formula: Area = 1/2 * base * height.

The Pythagorean theorem states that in a right triangle, the square of the length of the hypotenuse is equal to the sum of the squares of the lengths of the other two sides.