# RS Aggarwal Class 6 Math Fifteenth Chapter Polygons Exercise 15 Solution

## EXERCISE 15

### Some Basic Concepts STRAIGHT LINE: We know that by moving a pencil along the straight edge of a ruler, we get a straight line.

CURVE: By moving a pencil along a curved edge, we get a curve.

CLOSED FIGURE: A figure which begins and ends at the same point is called a closed figure.

OPEN FIGURE: A figure which does not end at the straight point is called an open figure.

SIMPLE CLOSED FIGURE: A closed figure which does not intersect itself is called a simple closed figure.

POLYGONS: A simple closed figure formed of three or more line segments is called a polygon.

SIDES: The line segments forming a polygon are called its sides.

VERTICES: The meeting point of a pair of sides of a polygon is called its vertex.

ADJACENT SIDES: Any two sides of a polygon having a common end point are called its adjacent sides.

DIAGONALS: A line segment joining two non-adjacent vertices of a polygon is called its diagonal.

TRIANGLE: A polygon of 3 sides is called a triangle.

QUADRILATERAL: A polygon of 4 sides is called a quadrilateral.

PENTAGON: A polygon of 5 sides is called a pentagon.

HEXAGON: A polygon of 6 sides is called a hexagon.

HEPTAGON: A polygon of 7 sides is called a heptagon.

OCTAGON: A polygon of 8 sides is called an octagon.

(1) Which of the following are simple closed figures? (2) Which of the following are polygons? (3) Fill in the blanks:

(i) A polygon is a simple closed figure formed by more than two line segments.

(ii) A polygon formed by three line segments is called a triangle.

(iii) A polygon formed by four line segments is called a quadrilateral.

(iv) A triangle has 3 sides and 3 angles.

(v) A quadrilateral has 4 sides and 4 angles.

(vi) A figure which ends at the starting point is called a closed figure.

Updated: May 30, 2022 — 12:37 pm