In geometry, a diagonal is **a line segment joining two vertices of a polygon or polyhedron**, when those vertices are not on the same edge. In matrix algebra, a diagonal of a square matrix is a set of entries extending from one corner to the farthest corner. There are also other, non-mathematical uses.

Contents

- 1 What is a diagonal and example?
- 2 How do you find diagonals in geometry?
- 3 What is meant by diagonals of quadrilateral?
- 4 What is diagonals and triangles?
- 5 What is diagonal in simple words?
- 6 How many diagonals are in a triangle?
- 7 How many diagonals are there in the following figure?
- 8 How do you calculate the diagonal of a triangle?
- 9 What are rhombus diagonals?
- 10 How many diagonals does a pentagon have?
- 11 How do you find a hypotenuse?
- 12 Does a circle have diagonals?
- 13 Is triangle a polygon?

## What is a diagonal and example?

The definition of diagonal is something with slanted lines or a line that connects one corner with the corner furthest away. An example of diagonal is a line going from the bottom left corner of a square to the top right corner.

## How do you find diagonals in geometry?

The number of diagonals in a polygon that can be drawn from any vertex in a polygon is three less than the number of sides. To find the total number of diagonals in a polygon, multiply the number of diagonals per vertex (n – 3) by the number of vertices, n, and divide by 2 (otherwise each diagonal is counted twice).

## What is meant by diagonals of quadrilateral?

A line segment drawn from one vertex of a quadrilateral to the opposite vertex is called a diagonal of the quadrilateral. For example, AC is a diagonal of quadrilateral ABCD, and so is BD.

## What is diagonals and triangles?

The diagonal triangle of a complete quadrangle is the triangle formed by its three diagonal points. If the quadrangle is a cyclic quadrilateral, then the circle is the polar circle of the diagonal triangle, i.e., each vertex is the inversion pole of the opposite side with respect to the circle.

## What is diagonal in simple words?

A diagonal is a straight line connecting the opposite corners of a polygon through its vertex.

## How many diagonals are in a triangle?

A triangle has no diagonals. A square has two diagonals of equal length, which intersect at the center of the square. The ratio of a diagonal to a side is. A regular pentagon has five diagonals all of the same length.

## How many diagonals are there in the following figure?

Know that a diagonal is defined as the line joining the opposite points of the polygone. Hence, there are five diagonals in the given figure.

## How do you calculate the diagonal of a triangle?

To find the length of the diagonal (or hypotenuse) of a right triangle, substitute the lengths of the two perpendicular sides into the formula a^{2} + b^{2} = c^{2}, where a and b are the lengths of the perpendicular sides and c is the length of the hypotenuse. Then solve for c.

## What are rhombus diagonals?

Every rhombus has two diagonals connecting pairs of opposite vertices, and two pairs of parallel sides. The two diagonals of a rhombus are perpendicular; that is, a rhombus is an orthodiagonal quadrilateral. Its diagonals bisect opposite angles.

## How many diagonals does a pentagon have?

Polygons: How Many Diagonals? (For pairs or groups of students) A diagonal of a regular polygon is a straight line joining two vertices which are not adjacent. Thus a square has two diagonals, and a regular pentagon has five, as shown below.

## How do you find a hypotenuse?

The hypotenuse is termed as the longest side of a right-angled triangle. To find the longest side we use the hypotenuse formula that can be easily driven from the Pythagoras theorem, (Hypotenuse)^{2} = (Base)^{2} + (Altitude)^{2}. Hypotenuse formula = √((base)^{2} + (height)^{2}) (or) c = √(a^{2} + b^{2}).

## Does a circle have diagonals?

A circle has infinite number of diameter and chords joining the infinite vertices. Both the diameters and chords are diagonals of the polygons of infinite number of vertices. Hence a circle has infinite number of diagonals.

## Is triangle a polygon?

A polygon is any shape made up of straight lines that can be drawn on a flat surface, like a piece of paper. Such shapes include squares, rectangles, triangles and pentagons but not circles or any other shape that includes a curve.