Page 297 - Start Up Mathematics_6

Solve Mentally Chapter 5
True or False Exercise 5.1
1. False 2. False 3. True 4. False 1. 9.3 cm 2. AB < CD 4. C lies between A and B
5. True 6. True
Exercise 5.2
Fill in the Blanks 1. ∠PQR is greater; either observation or tracing
1. parallel, intersecting 2. triangle 2. Sum = 180° 4. (a) East (b) South (c) North
3. diameter 4. 1 and 6 5. 4 5. (a) 9 (b) 3 (c) 3
6. (a) 150° (b) 90° (c) 105°
6. concurrent 7. equidistant
7. obtuse, acute, zero, acute, reflex, straight, right, reflex,
Answer in One Word or a Line acute, obtuse
1. If a circle is divided into 4 equal parts then each sector 8. 90° 9. 14 right angles 10. 10 right angles
is called a quadrant, 4. Try It Out!
2. No (a) Equilateral triangle
3. A polygon is a simple closed figure formed by straight (b) Not possible as the sum of two sides should be greater
lines. Three polygons having four sides are square, rect- than the third side
angle and trapezium. (c) Isosceles triangle
4. No Exercise 5.3
5. A line extends in both directions indefinitely, a line seg- 1. (a) Equilateral (b) Scalene (c) Scalene (d) Isosceles
ment has definite length and a ray extends in one direction 2. (a) Obtuse (b) Right (c) Acute
only. 3. A triangle refers to its three sides and triangular region
Let’s Evaluate refers to the interior of the triangle together with the
1. (a) 2r (b) semicircles (c) sector triangle.
2. (a) True (b) True (c) False (d) False 4. (a) three, three, three (b) six (c) obtuse triangle
(e) True (f) True (d) acute (e) right
1 5. (a) False (b) False (c) False
3. (a) (b) 3 times
6 (d) False (e) False (f) True
Thinking Skills (g) True (h) False
1. (a) No, since the lines are intersecting in between. 6. A trapezium is a quadrilateral in which a pair of sides is
(b) No, since the lines are intersecting in between. parallel.
A parallelogram is a quadrilateral in which opposite sides
2. A semicircle is both a sector and a segment.
are parallel.
3. (a) PQ, RS, UT and TS (b) UT, RS and PQ A rectangle is a parallelogram in which each angle is right
(c) OR, OT, OS and OU (all radii) (d) a sector angle.
(e) a segment 7. In a regular polygon all sides are equal and all the angles

4. (a) major arc (b) minor arc are equal, while in an irregular polygon all sides and all
5. (a) Triangles–13 (b) Squares–14 angles are not equal.
Exercise 5.4
Exemplar Problems
1. a 2. 3 3. ray AB 1. (a) Chalk box, Rubix cube (b) Book, brick
(c) Heap of wheat in a field, an ice cream cone
4. Both figures have 3 line segments. No, because it is (d) Marbles, football (e) Drum, chalk
not a closed figure. 2. (a) Sphere (b) Cuboid (c) Conical (d) Cube
5. (a) ∠AEB, ∠ADE, ∠BAE, ∠BCE (e) Cuboid (f) Cuboid (g) Cuboid (h) Cylinder
(b) ∠BCD, ∠ADC, ∠DAB, ∠ABC Review Exercises
6. (a) CP and AB (b) OA, OB, OC, OP (c) CP Multiple Choice Questions
1. b 2. a 3. c 4. d 5. d 6. d 7. c
(d) (e)
Solve Mentally
True or False
1. True 2. True 3. False 4. True 5. True

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