Tag: types of angle

Questions Related to types of angle

What is the acute angle between the lines y = 3x + 2 and y = 4x + 9?

  1. 4.4$\displaystyle ^{\circ}$

  2. 28.3$\displaystyle ^{\circ}$

  3. 5.2$\displaystyle ^{\circ}$

  4. 18.6$\displaystyle ^{\circ}$

  5. none of these


Correct Option: A
Explanation:

$y=3x+2$

$m _1=3$
$=>tan\theta _1=3$
$=>\theta _1=tan^{-1}(3)$
$=>\theta _1=71.57^{0}$
Again,
$y=4x+9$
$=>m _2=4$
$=>tan\theta _2=4$
$=>\theta _2=tan^{1}(4)$
$=>\theta _2=75.96^{0}$
$\therefore$ Angle between the lines
$=\theta _2-\theta _1$
$=75.96-71.56$
$=4.4^{0}$

An angle that is $\displaystyle  { 1 }^{ o }$ less than right angle is:

  1. Reflex angle

  2. Straight angle

  3. Obtuse angle

  4. Acute angle


Correct Option: D
Explanation:

Right angle measures $\displaystyle  { 90 }^{ o }$
$\displaystyle  { 1 }^{ o }$ less of right angle = $\displaystyle { 90 }^{ o }-{ 1 }^{ o }$
$\displaystyle { 89 }^{ o }$
Which is an acute angle.

Acute angle is the angle which is greater than $\displaystyle { 0 }^{ o }$ and less than $\displaystyle { 90 }^{ o }$.

Obtuse angle is the angle which is greater than $\displaystyle { 90}^{ o }$ and less than $\displaystyle {180 }^{ o }$.
Right angle is the angle which is equal to $90^o$.
Reflex angle is the angle which is greater than $\displaystyle {180}^{ o }$ and less than $\displaystyle {360 }^{ o }$.

If the angle is greater than $\displaystyle { 0 }^{ o }$ and less than $\displaystyle { 90 }^{ o }$, then the angle is known as:

  1. Obtuse angle

  2. Right angle

  3. Acute angle

  4. Reflex angle


Correct Option: C
Explanation:

Acute angle is the angle which is greater than $\displaystyle { 0 }^{ o }$ and less than $\displaystyle { 90 }^{ o }$.

Obtuse angle is the angle which is greater than $\displaystyle { 90}^{ o }$ and less than $\displaystyle {180 }^{ o }$.
Right angle is the angle which is equal to $90^o$.
Reflex angle is the angle which is greater than $\displaystyle {180}^{ o }$ and less than $\displaystyle {360 }^{ o }$.

The sum of two acute angles can be:

  1. Acute angles

  2. Obtuse angles

  3. Right angles

  4. All of the above


Correct Option: D
Explanation:

Let one angle is $\displaystyle { 30 }^{ o }$ and the other angle is $\displaystyle { 40 }^{ o }$ then sum $\displaystyle { 70 }^{ o }$. which is an acute angle.
Let one angle be $\displaystyle { 70 }^{ o }$ and other angle is $\displaystyle { 80 }^{ o }$, then sum is $\displaystyle { 150 }^{ o }$ which is obtuse angle.
Let one angle is $\displaystyle { 45 }^{ o }$ and another angle is $\displaystyle { 45 }^{ o }$ then sum is $\displaystyle { 90 }^{ o }$ which is right angle.

Which of the following is obtuse angle?

  1. Two right angles

  2. One and half right angles

  3. One right angle

  4. Half a right angle


Correct Option: B
Explanation:

Right angle $=90^{\circ}$

One and half right angle $=\dfrac { { 90 }^{ \circ  } }{ 2 } +{ 90 }^{ \circ  }={ 135 }^{ \circ  }$
which is greater than $90^{\circ}$
So it is an obtuse angle .
Option $B$ is correct.

Range of an obtuse angle is:

  1. $[0˚, 90˚)$

  2. $(0˚, 90˚]$

  3. $[90˚, 180˚)$

  4. $(90˚, 180˚)$


Correct Option: D
Explanation:

Acute angle is the angle which is greater than $\displaystyle { 0 }^{ o }$ and less than $\displaystyle { 90 }^{ o }$.

Obtuse angle is the angle which is greater than $\displaystyle { 90}^{ o }$ and less than $\displaystyle {180 }^{ o }$.
Right angle is the angle which is equal to $90^o$.
Reflex angle is the angle which is greater than $\displaystyle {180}^{ o }$ and less than $\displaystyle {360 }^{ o }$.

At which one of the following times is the angle between the hands of the clock equal to one straight angle?

  1. $12 : 00$

  2. $12 : 30$

  3. $8 : 43$

  4. $8 : 00$


Correct Option: B
Explanation:

A straight angle can be formed when the hour and minute hands becomes $180^0$ and that happens at $12:30$

An angle which measures more than $90^o$ but less than $180^o$ is called ___________.

  1. Acute

  2. Obtuse

  3. Right

  4. None of these


Correct Option: B
Explanation:

An angle which measures more than $90^o$ but less than $180^o$ is called as an obtuse angle.

The measure of an acute angle is always $< 90^{o}$

  1. True

  2. False


Correct Option: A
Explanation:

Acute angles are angles whose measurements fall between 0 and 90 degrees.

 $\therefore$ The above statement is true.

Mark the correct alternative of the following.
An angle of measure $140^o$ is?

  1. An acute angle

  2. An obtuse angle

  3. A straight angle

  4. A complete angle


Correct Option: B
Explanation:

An angle that measures $<180^o$ but $>90^o$ is called an obtuse angle.

Here it is given $140^o$, so it is an obtuse angle.