# Given here are some figures

Classify each of them on the basis of the following.

(a) Simple curve

(b) Simple closed curve

(c) Polygon

(d) Convex polygon

(e) Concave polygon

**Solution:**

(a) Simple curve - A simple curve is a curve that does not cross itself and can be both open and closed.

(b) Simple closed curve - In simple closed curves the shapes are closed by line segments or by a curved line.

(c) Polygon - A simple closed curve made up of only line segments is called a polygon.

(d) Convex polygon - A convex polygon is a closed figure where all its interior angles are less than 180° and the vertices are pointing outwards.

(e) Concave polygon - A concave polygon is defined as a polygon with one or more interior angles greater than 180°

**ā Check: **NCERT Solutions Class 8 Maths Chapter 3

**Video Solution:**

## Given here are some figures. Classify each of them on the basis of the following. (a) Simple curve (b) Simple closed curve (c) Polygon (d) Convex polygon (e) Concave polygon

NCERT Solutions Class 8 Maths Chapter 3 Exercise 3.1 Question 1

**Summary:**

(a) The figures (1), (2), (5) , (6) and (7) are Simple curves. (b) The figures (1), (2) , (5), (6) and (7) are Simple Closed Curves. (c) The figures (1) and (2) are Polygons. (d) The figure (2) is a Convex polygon. (e) The figure (1) is a Concave polygon.

**ā Related Questions:**

- How many diagonals does each of the following have? (a) A convex quadrilateral (b) A regular hexagon (c) A triangle
- What is the sum of the measures of the angles of a convex quadrilateral? Will this property hold if the quadrilateral is not convex? (Make a non-convex quadrilateral and try!)
- Examine the table. (Each figure is divided into triangles and the sum of the angles deduced from that.) What can you say about the angle sum of a convex polygon with number of sides? (a) 7 (b) 8 (c) 10 (d) n
- What is a regular polygon? State the name of a regular polygon of (i) 3 sides (ii) 4 sides (iii) 6 sides

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