Q:
# What is a concave quadrilateral?

**A concave quadrilateral is a shape that has four sides and contains an indentation where the internal angle is greater than 180 degrees.** The most common example of a concave quadrilateral is a shape whose left and right sides resemble a triangle; however, instead of meeting in a straight line as a base, they meet at another vertex angled towards their upper vertex.

Credit:
fdecomite
CC-BY 2.0

The definition of concave is curved inwards. When applied to polygons, this means that the shape must have some sort of dent in it (at least one vertex pointing inwards). The definition of a quadrilateral is a two-dimensional figure that has four sides. Therefore, a concave quadrilateral must satisfy both of these definitions. Furthermore, a concave quadrilateral must also satisfy the definition of a simple shape. A shape that is not simple intersects with itself. A concave quadrilateral is simple, then, by the fact that it does not intersect with itself at any point.

A more accurate definition of a quadrilateral is a polygon whose internal angles add up to 360 degrees. In a square, for example, four 90-degree angles are added together for 360 degrees. Since a concave polygon has one angle measuring greater than 180 degrees, the sum of its three other angles must be 180.

Learn more about Shapes-
Q:
## How many sides does a rectangle have?

A: A rectangle is a quadrilateral that has four sides. In a rectangle, the opposite sides are of equal length and also parallel. Because of this, a rectangle ... Full Answer >Filed Under: -
Q:
## What is a polygon with four sides and four angles called?

A: A polygon with four sides and four angles is called a quadrilateral. Quadrilaterals are two-dimensional, closed shapes with angle measurements that add up ... Full Answer >Filed Under: -
Q:
## How many sides are there in a parallelogram?

A: A parallelogram is a two-dimensional rhomboid or quadrilateral with four sides. The four sides, or edges, consist of two pairs, each with the opposite side... Full Answer >Filed Under: -
Q:
## How many sides does a trapezium have?

A: A trapezium is a quadrilateral that consists of four sides that are not parallel. If one pair of these sides were parallel, it would be called a trapezoid.... Full Answer >Filed Under: