Ad
related to: formula for angles in polygon with one base and two pairs of sides
Search results
Results From The WOW.Com Content Network
The sum of all the internal angles of a simple polygon is π(n−2) radians or 180(n–2) degrees, where n is the number of sides. The formula can be proved by using mathematical induction: starting with a triangle, for which the angle sum is 180°, then replacing one side with two sides connected at another vertex, and so on. The sum of the ...
A simple (non-self-intersecting) quadrilateral is a parallelogram if and only if any one of the following statements is true: [2] [3] Two pairs of opposite sides are parallel (by definition). Two pairs of opposite sides are equal in length. Two pairs of opposite angles are equal in measure. The diagonals bisect each other.
The cotangents of two adjacent angles sum to 0, as do the cotangents of the other two adjacent angles. [16]: p. 26 One bimedian divides the quadrilateral into two quadrilaterals of equal areas. [16]: p. 26 Twice the length of the bimedian connecting the midpoints of two opposite sides equals the sum of the lengths of the other sides.
Any non-self-crossing quadrilateral with exactly one axis of symmetry must be either an isosceles trapezoid or a kite. [5] However, if crossings are allowed, the set of symmetric quadrilaterals must be expanded to include also the crossed isosceles trapezoids, crossed quadrilaterals in which the crossed sides are of equal length and the other sides are parallel, and the antiparallelograms ...
The extended base of a triangle (a particular case of an extended side) is the line that contains the base. When the triangle is obtuse and the base is chosen to be one of the sides adjacent to the obtuse angle , then the altitude dropped perpendicularly from the apex to the base intersects the extended base outside of the triangle.
The corresponding angles as well as the corresponding sides are defined as appearing in the same sequence, so for example if in a polygon with the side sequence abcde and another with the corresponding side sequence vwxyz we have vertex angle a appearing between sides a and b then its corresponding vertex angle v must appear between sides v and w.
Every finite set of points in the plane that does not lie on a single line can be connected to form the vertices of a simple polygon (allowing 180° angles); for instance, one such polygon is the solution to the traveling salesperson problem. [36] Connecting points to form a polygon in this way is called polygonalization. [37]
In a parallelogram, where both pairs of opposite sides and angles are equal, this formula reduces to = . Alternatively, we can write the area in terms of the sides and the intersection angle θ of the diagonals, as long as θ is not 90°: [18]