In plane Euclidean geometry, a rhombus (plural rhombi or rhombuses) is a simple a parallelogram in which a diagonal bisects an interior angle Using congruent triangles, one can prove that the rhombus is symmetric across each of these. Learn about and revise angles, lines and multi-sided shapes and their properties with this BBC Bitesize The sum of interior angles in a quadrilateral is °. The interior angles of a polygon are those angles at each vertex that are on the inside of the polygon. There is one per vertex. So for a polygon with N sides. Formula for the area of a rhombus. s is the length of any side a is any interior angle sin is the sine function Perimeter of various polygon types. Perimeter of a . By Mark Ryan. Everything you need to know about a polygon doesn't necessarily fall within its sides. You may need to find exterior angles as well as interior. By following 2 properties of a rhombus, interior angles can be calculated (1) Diagonals of a rhombus bisect each other at right angle. So, 4 right triangles will . And the diagonals "p" and "q" of a rhombus bisect each other at right angles. If you can draw your Rhombus, try the Area of Polygon by Drawing tool. Intermediate Geometry: How to find an angle in a rhombus. Study concepts What is the measurement of each of the other two interior angles? Possible.