Measure and classify each angle: Angle Measure Type ∠ A O B ∠ A O C ∠ B O C ∠ D O C ∠ D O A ∠ D O B

To measure the the given angles place the midpoint of the protractor on the vertex of the angle. Adjust the protractor so that one arm of the angle is along the straight edge of the protractor. Read the scale which has the 0 ° mark coinciding with the straight-edge. Example: Measuring ∠ B O C we get it is 90 ° . We know that, An angle whose measure is less than 90 ° and greater than 0 ° is known as acute angle. An angle whose measure is more than 90 ° and less than 180 ° is obtuse angle. An angle whose measure is 90 ° is right angle. An angle whose measure is 180 ° is straight angle. The completed table is as follows: Angle Measure Type ∠ A O B 40 ° acute ∠ A O C 130 ° obtuse ∠ B O C 90 ° right ∠ D O C 90 ° right ∠ D O A 140 ° obtuse ∠ D O B 180 ° straight

Which direction will you face if you start facing East and make 1 2 of a revolution clockwise?

Given, to find the direction that we face starting from East and making 1 2 revolution. From the figure, we can see that facing East and make 1 2 of a revolution clockwise that means making 180 o results West. Hence, the required answer is West.

Match the following: (i) Straight angle (a) Less than one-fourth of a revolution (ii) Right angle (b) More than half of revolution (iii) Acute angle (c) Half of a revolution (iv) Obtuse angle (d) One-fourth of a revolution (v) Reflex angle (e) Between 1 4 and 1 2 of a revolution

We have, Straight angle is 180 ° and one complete revolution is 360 ° Now, 180 ° 360 ° = 1 2 Therefore, straight angle is half of revolution. Right angle is 90 ° and 90 ° 360 ° = 1 4 Therefore, right angle is 1 4 of revolution. Acute angle is an angle between 0 ° to 90 ° . Therefore, it implies less than one-fourth of a revolution. Obtuse angle is an angle between 90 ° to 180 ° and 180 ° 360 ° = 1 2 Therefore, it implies between 1 4 and 1 2 of a revolution. Reflex angle is an angle greater than 180 o . Thus, it implies more than half a revolution. Hence, the completed table is as follows: (i) Straight angle (c) Half of a revolution (ii) Right angle (d) One-fourth of a revolution (iii) Acute angle (a) Less than one-fourth of a revolution (iv) Obtuse angle (e) Between 1 4 and 1 2 of a revolution (v) Reflex angle (b) More than half of a revolution

EASY

Earn 100

The supplementary angle of an obtuse angle is .

50% studentsanswered this correctly

Important Questions on Understanding Elementary Shapes

EASY

Mathematics>Geometry>Understanding Elementary Shapes>Types of Angles

If the sum of two angles is _____, then they are called supplementary

MEDIUM

Mathematics>Geometry>Understanding Elementary Shapes>Types of Angles

On a clock, there are two instants between

12

noon and

1

PM, when the hour hand and the minute hand are at right angles. The difference in minutes between these two instants is written as

a + \frac{b}{c},

where

a, b and c

are positive integers, with

b < c

and

\frac{L}{c}

in the reduced form. What is the value of

a + b + c ?

EASY

Mathematics>Geometry>Understanding Elementary Shapes>Types of Angles

Find the angle measure between the hands of the clock in each figure:
Question Image

EASY

Mathematics>Geometry>Understanding Elementary Shapes>Types of Angles

Write down the measures of some acute angles.(Give at least two examples of each)

MEDIUM

Mathematics>Geometry>Understanding Elementary Shapes>Types of Angles

Measure and classify each angle:

Question Image

Angle	Measure	Type
$∠ A O B$
$∠ A O C$
$∠ B O C$
$∠ D O C$
$∠ D O A$
$∠ D O B$

EASY

Mathematics>Geometry>Understanding Elementary Shapes>Types of Angles

An angle which is greater than

180^{o}

but less than

360^{o}

is known as

HARD

Mathematics>Geometry>Understanding Elementary Shapes>Types of Angles

Which direction will you face if you start facing East and make

\frac{1}{2}

of a revolution clockwise?

EASY

Mathematics>Geometry>Understanding Elementary Shapes>Types of Angles

Draw a triangle ABC, measure its angles using a protractor and write their sum as the final answer without degree symbol.

MEDIUM

Mathematics>Geometry>Understanding Elementary Shapes>Types of Angles

Match the following:

(i)	Straight angle	(a)	Less than one-fourth of a revolution
(ii)	Right angle	(b)	More than half of revolution
(iii)	Acute angle	(c)	Half of a revolution
(iv)	Obtuse angle	(d)	One-fourth of a revolution
(v)	Reflex angle	(e)	Between $\frac{1}{4}$ and $\frac{1}{2}$ of a revolution