Samacheer Kalvi 6th Maths Solutions Term 1 Chapter 4 Geometry Ex 4.2

You can Download Samacheer Kalvi 6th Maths Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 6th Maths Solutions Term 1 Chapter 4 Geometry Ex 4.2

Question 1.
Use any number of the given dots to make different angles.

Solution:

Question 2.
Name the vertex and sides that form each angle.

Solution:

Question 3.
Pick out the Right angles from the given figures.

Solution:
(i), (iii) and (v) are Right Angles.

Question 4.
Pick out the Acute angles from the given figures.

Solution:
(i), (iii) and (iv) are the Acute Angles.

Question 5.
Pick out the Obtuse Angles from the given figures.

Solution:
(i) and (ii) are the Obtuse Angles.

Question 6.
Name the angle in each figure given below in all the possible ways.

Solution:
(i) ∠LMN, ∠NML, ∠M
(ii) ∠PQR, ∠RQP, ∠Q
(iii) ∠MNO, ∠ONM, ∠N
(iv) ∠TAS, ∠SAT, ∠A
(v) ∠XYZ, ∠ZYX, ∠Y
(vi) ∠ADB, ∠BDA, ∠D

Question 7.
Say True or False.

1. 20° and 70° are complementary.
2. 88° and 12° are complementary.
3. 80° and 180° are supplementary.
4. 0° and 180° are supplementary.

Solution:

1. True
2. False
3. False
4. True

Question 8.
Draw and label each of the angles
(i) ∠NAS = 90°
(ii) ∠BLG = 35°
(iii) ∠SMC = 145°
Solution:

Question 9.
Identify the types of angles shown by the hands of the given clock.

Solution:
(i) Obtuse Angle.
(ii) Zero Angle.
(iii) Straight Angle.
(iv) Acute Angle.
(v) Right Angle.

Question 10.
Find the supplementary ‘l’ complementary angles in each case.

Solution:
(i) If two angles add up to 180°, they are supplementary.
We know that the straight angle ∠CBC = 180°
Given ∠CBD = 25°
∴ ∠DBA = 180° – 25° = 155°
∴ Supplementary ∠DBA = 155°

(ii) If two angles add upto 90°, they are complementary
Given ∠ABC = 25°
∠CBD = 30°
∴ ∠DBA = 90° – 30° = 60°
∴ Complementary angle ∠DBA = 60°

(iii) Given ∠CBA = 90°
∠CBD = 46°
∴ ∠DBA = 90° – 46° = 44°
We know that the sum of two angles is 90°, then they are complementary
∴ Complementary angle ∠DBA = 44°

(iv) Given ∠DBE = 180°
∠DBC = 67°
∴ ∠CBE = 180° – 67° = 113°
Here ∠DBC + ∠DBE = 180°
∴ Supplementary angle ∠CBE = 113°

Objective Type Questions

Question 11.
In this Figure, which is not the correct way of naming an angle?

(a) ∠Y
(b) ∠ZXY
(c) ∠ZYX
(d) ∠XYZ
Solution:
(b) ∠ZXY

Question 12.
In this Figure, ∠AYZ = 45°. If the point ‘A’ is shifted to point ‘B’ along the ray, then the measure of ∠BYZ is ____

(a) more than 45°
(b) 45°
(c) less than 45°
(d) 90°
Solution:
(b) 45°
Hint: ∠XYZ = ∠BYZ = ∠AYZ