Class 6 Maths Basic Geometrical Ideas Quadrilaterals

A four-sided polygon is termed as a quadrilateral. Below is the image of a quadrilateral ABCD.

Quadrilateral has four sides (line segments) AB, BC, CD, DA

Quadrilateral has four angles, ∠ABC, ∠BCA, ∠CDA, ∠DAB

Quadrilateral has four vertices, A, B, C, D.

∠A and ∠B are adjacent angles. Similarly, ∠B and ∠C, ∠C and ∠D, ∠D and ∠A are also adjacent angles.

∠A and ∠C, ∠B and ∠D are opposite angles.

Side AB and BC are adjacent side. Similarly, sides BC and CD, CD and DA, DA and AB are also adjacent sides.

Side AB and CD, BC and DA are opposite sides.

Quadrilateral being a closed curve, has three regions; interior, exterior and boundary.

Quadrilateral are divided into several types, each one having some specific properties. You will learn those in higher classes

Question: Draw a rough sketch of a quadrilateral PQRS. Draw its diagonals. Name them. Is the meeting point of diagonals in the interior or exterior of the quadrilaterals?

Solution:

Above is the diagram of a quadrilateral PQRS. Diagonals are PR and SQ.

Meeting point of diagonals is O. O lies interior of the quadrilaterals.

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