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Learn to identify quadrilaterals such as kites, trapezoids, parallelograms, rhombuses, rectangles, and squares by side length, presence of parallel sides, and angle type. Created by Sal Khan.

## Want to join the conversation?

• Is a square always a rombus?
• Yes, because a rhombus is a parallelogram with equal sides, and a square is also a parallelogram with equal sides.

The difference is that the square also has four right angles.

Rhombus
- 4 equal sides
- parallelogram

Square
- 4 equal sides
- parallelogram
- 4 equal 90° angles

Notice that the square - by definition - always meets the criteria for a rhombus. So every square is also a rhombus!

However, not every rhombus is a square: if the rhombus has 2 acute angles and 2 obtuse angles, then it is just a rhombus.

Hope this helps!
• is there any proof that if a parallelogram has one right angle, it's a rectangle?
• Well, the definiton of parallelogram is that both pairs of sides are parallel - what I mean by pairs of sides is tricky to explain without a drawing, so I'm gong to assume you already know it. The diefinition of right angle is a measure of 90 deg, which means the two lines are perpendicular to each other. So with some logic you can see that if one line a is perpendicular to line b, and line c is parallel to line a, then line b has to be perpendicular to c as well. Right? And that means the angle between b and c has to be a right angle as well. You can keep going around the parallelogram and get four right angles, which means it's a rectangle
• Just a quick question that's been on my mind:

Is it possible for any trapezoid to have the pair of parallel sides having equal length? If it did, it would be considered a square, right? But is a square considered a trapezoid? :/
• No. By definition trapezoids will always have only one pair of parallel sides. Having a trapezoid with two parallel sides of equal length would give you two pairs of parallel sides, which would be considered a rectangle instead of a trapezoid. A square will also always have two pairs of parallel sides, and thus cannot be a trapezoid.
• What is a kite?
• Im sure a kite is a quadrilateral that is shaped like a kite. You can search up different types of them.
• is a square always a rhombus ?
• A square is defined as a quadrilateral with 4 equal sides and 4 equal angles.

A rhombus is defined as a quadrilateral with 4 equal sides.

Comparing these definitions, we see that, yes, every square is a rhombus. However, not every rhombus is a square (for example, think of a tall and thin diamond shape).
• i am still confused.for example,at why did you choose like the rhombus instead of the parallelogram.
• He picked rhombus instead of parallelogram because rhombus is the most specific item from the list. The question asks for us to "be as specific as possible" so while it is a parallelogram, that answer would be wrong.
Rhombus is more specific because rhombi are a subset of parallelograms, meaning all rhombi are parallelograms, but not all parallelograms are rhombi. Rhombus is a parallelogram with all equal sides.
• What is a trapezoid and isosceles trapezoid?