The DAV Maths Book Class 4 Solutions and DAV Class 4 Maths Chapter 10 Worksheet 3 Solutions of Angles offer comprehensive answers to textbook questions.
DAV Class 4 Maths Ch 10 WS 3 Solutions
Question 1.
Use the protractor and measure the following angles.
Answer:
45°
Answer:
70°
Answer:
110°
Answer:
35°
Answer:
90°
Answer:
115°
Answer:
120°
Answer:
180°
Question 2.
Construct angles of the following measures. Label the angles and name them.
(a) 40°
Answer:
∠PQR = 40°
(b) 75°
Answer:
∠ABC = 75°
(c) 90°
Answer:
∠XYZ = 90°
(d) 100°
Answer:
∠LMN = 100°
(e) 120°
Answer:
∠DEF = 120°
(f) 155°
Answer:
∠STR = 155°
DAV Class 4 Maths Chapter 10 Worksheet 3 Notes
Measuring Angles:
The standard unit of an angle is Degree. The symbol (°) is used for degree. We use protractor to measure an angle.
There are two rows of numbers marked on the protractor. Numbers are marked from 0 to 180. It has two scales in reverse order. Measuring ZABC
- Step I: Place the centre of the protractor on the vertex B of ∠CBA. Adjust the arm BA.
- Step II: Look for the scale which begins with zero.
- Step III: Read the mark on the protractor where the other arm (\(\overrightarrow{\mathrm{BC}}\)) of the angle crosses the scale on the protractor.
∠ABC = 80° as shown in figure. Angles opening to left increases from left to right. Angles opening to right increases from right to left.