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## Class 9 math (India)

### Course: Class 9 math (India)>Unit 7

There are many different types of quadrilaterals. A quadrilateral is defined as a two-dimensional shape with four sides, four vertices, and four angles. There are two main types: concave and convex. There are also various subcategories of convex quadrilaterals, such as trapezoids, parallelograms, rectangles, rhombi, and squares. Created by Sal Khan.

## Want to join the conversation?

• It is and do quadrilaterals have to be closed?
• Yes, they have to be closed. In fact, all polygons have to be closed.
• what is the formula to find the area of a diamond ??????????
• The area formula for a Rhombus is:

A = (1/2) (d1) (d2)

d1 & d2 represent the length of the 2 diagonals
• I do not understand the difference between a quadrilateral, parallelogram, rhombus?
• the rhombus is a slanted square and the parallelogram is a slanted rectangle. they both are quadrilateral. The term 'quadrilateral' means 4 sides. so a square, rhombus etc. are quadrilaterals. Hope this helps! :)
• Does the sides have to be equal to be a quad.
• not necessarily. the weird pink shape that he showed did not have equal sides
• Can you give 50 votes for me to get the badge pweez
• ok I did now help him get a baj
• How does a square go under the description of both the rectangle and rhombus? Is it because a square and a rectangle and rhombus all have 2 parallel sides? or is it because of something else?
• A rectangle has 4 straight sides and 4 right angles.

A rhombus must have opposite equal angles and 4 equal sides.

A square has 2 sets of opposite right angles and 4 straight, equal sides, so it fits into both categories.

Hope this helps!
• skibigy dop
• ¿Could a Perfect Hexagon be a parallelogram?
• Even though you may think there is another parallel side for each side in a regular hexagon, the definition of a parallelogram is a four-sided plane rectilinear figure with opposite sides parallel.

I hope this helped!
• Can someone give me an overview of the differences between Rhombi, Parallelograms and Rectangles?