Two angles that have the sum of 180 degrees are supplementary angles. Given one supplementary angle A, a person can find the other supplementary angle B by subtracting A from 180 degrees.Continue Reading
If one of the supplementary angles is 40, then the other supplementary angle is 180 – 40, or 140 degrees. When added together, two supplementary angles also form a straight angle; thus, a straight angle is also equal to 180 degrees.
In geometry, there are other different types of angles besides supplementary angles, such as acute and obtuse angles. While an acute angle is less than 90 degrees, an obtuse angle is more than 90 degrees but less than 180 degrees. In the example given above, the 40-degree angle is an acute angle, and the 140-degree angle is an obtuse angle.Learn more about Shapes
Every triangle has three angles, and the sum of those angles is always 180 degrees. This is true whether the triangle is an equilateral, isosceles, scalene or right triangle.Full Answer >
The sum of the interior angles of an equilateral triangle equals 180 degrees. This stems from the fact that the combined interior angles of any given triangle always add up to this same amount, according to the Monterey Institute for Technology and Education.Full Answer >
The properties of a trapezium are that it has four sides, none of which are parallel; the sum of its angles equals 360 degrees; and any three sides are greater than the fourth. A trapezium is a quadrilateral, meaning it has four sides, but it is not a common figure in geometry.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.Full Answer >