CLASS-6 MATHS CHAPTER-4 BASIC GEOMETRICAL IDEAS

                                                                         Chapter-4

Basic geometrical ideas

                                                                                       Exercise-4.1

Question 1:Use the figure to name:

(a) Five points

(b) A line

(c) Four rays

(d) Five line segments

Answer:(a) The five points are D, E, O, B, and C.

(b) 

(c) 

(d) 

Question 2:Name the line given in all possible (twelve) ways, choosing only two letters at a time from the four given.

Answer:

Exercise-4.2

Question 3:Use the figure to name:

(a) Line containing point E.

(b) Line passing through A.

(c) Line on which O lies

(d) Two pairs of intersecting lines.

Answer:

(a) 

(b) 

(c) 

(d) , 

Question 4:How many lines can pass through (a) one given point? (b) Two given points?

Answer:(a) Infinite number of lines can pass through a single point.

(b) Only one line can pass through two given points.

Question 5:

Draw a rough figure and label suitably in each of the following cases:

(a) Point P lies on.

(b) and intersect at M.

(c) Line l contains E and F but not D.

(d) and meet at O.

Answer:

(a)

(b)

(c)

(d)

Question 6: Consider the following figure of line. Say whether following statements are true or false in context of the given figure.

(a) Q, M, O, N, P are points on the line.

(b) M, O, N are points on a line segment.

(c) M and N are end points of line segment.

(d) O and N are end points of line segment.

(e) M is one of the end points of line segment.

(f) M is point on ray.

(g) Ray is different from ray.

(h) Ray is same as ray.

(i) Ray is not opposite to ray.

(j) O is not an initial point of.

(k) N is the initial point of and.

Answer:

(a) True

(b) True

(c) True

(d) False

(e) False

(f) False

(g) True

(h) False

(i) False

(j) False

(k) True

Exercise-4.3

Question 1:Classify the following curves as (i) Open or (ii) Closed.

Answer:

(a) Open

(b) Closed

(c) Open

(d) Closed

(e) Closed

Question 2:Draw rough diagrams to illustrate the following:

(a) Open curve (b) Closed curve.

Answer:

(a) Open curve

(b) Closed curve

Question 3:

Draw any polygon and shade its interior.

Answer:

Question 4:Consider the given figure and answer the questions:

(a) Is it a curve? (b) Is it closed?

Answer:

(a) Yes

(b) Yes

Question 5:Illustrate, if possible, each one of the following with a rough diagram:

(a) A closed curve that is not a polygon.

(b) An open curve made up entirely of line segments.

(c) A polygon with two sides.

Answer:

(a)

(b)

(c) This is not possible as the polygon having the least number of sides is a triangle, which has three sides in it.

Exercise-4.4

Question 1:Name the angles in the given figure.

Answer:

∠BAD, ∠ADC, ∠DCB, ∠CBA

Question 2:In the given diagram, name the point (s)

(a) In the interior of ∠DOE

(b) In the exterior of ∠EOF

(c) On ∠EOF

Answer:

(a) A

(b) C, A, D

(c) B, E, O, F