CHAPTER 3
Understanding Quadrilaterals
Class 8 Maths Chapter 3 Understanding Quadrilaterals NCERT
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Class 8 Maths Chapter 3 Understanding Quadrilaterals NCERT
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Exercise 3.1
Given here are some figures :
Q1. Given 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
Answer :
Figure No. Description / Type Classification
(1) Closed figure made of straight lines, with one interior angle greater than 180° Concave polygon
(2) Closed figure made of straight lines, all angles less than 180° Convex polygon
(3) Closed curved figure (two ovals) Simple closed curve
(4) Star shape (crossing lines) Polygon (not simple)
(5) Two circles joined, boundary crosses itself Not a simple curve
(6) Closed curved figure (like capsule shape) Simple closed curve
(7) Closed figure with straight and curved edges, one inward angle Concave polygon
(8) Line with two ovals (open shape) Simple curve (open)
Q2. What is a regular polygon?
Answer:
A regular polygon is a polygon that has all sides equal in length and all angles equal in measure.
Q3. State the name of a regular polygon of:
(i) 3 sides (ii) 4 sides (iii) 6 sides
Answer :
(i) 3 sides - Equilateral triangle
(ii) 4 sides - Square
(iii) 6 sides - Regular hexagon
