In Maths chapter 16 Understanding Shapes – II(Quadrilaterals) covers angle sum property of a quadrilateral, classification of polygons, the concept of polygons, concept of curves, concept of quadrilaterals, different types of curves, exterior angles of a polygon and its property, interior angles of a polygon, properties of a parallelogram, properties of a square, properties of the kite, properties of a rectangle, properties of a rhombus, properties of the trapezium.
Quadrilaterals are polygons that have four sides. These figures have some basic components like sides (the four straight lines which form this closed curve), adjacent sides (the two sides next to each other), angles (the inclination of the sides with each other), diagonals (the lines connecting the opposite angles), opposite angles (the lines formed by two different sets of lines which are opposite to each other).
Special Quadrilaterals are classified into six types: square, rectangle, parallelogram, rhombus, kite, and trapezium. All six of these figures contain four vertices and four sides that enclose four angles. Thus, the sum of a quadrilateral's four angles equals 360°. This number is determined from the internal angle's equation of the polygon (n - 2) multiplied by 180°.
Further in RD Sharma Maths chapter 16 Understanding Shapes – II (Quadrilaterals), The concept of quadrilaterals includes sides, adjacent sides, opposite sides, angle, adjacent angle, and opposite angles. The types of curves such as closed curves and simple curves. The prominent subtopics of the chapter include the interior and exterior of a quadrilateral. The figure of a convex quadrilateral is also taught, which states that any quadrilateral with all the vertices bulging out is a convex quadrilateral. A quadrilateral with any vertex drawn inwards is a concave quadrilateral. The chapter also elaborates on the interior angle sum property and the exterior angle property. These two properties are crucial in helping students find out the angles in any given quadrilateral.