Tag: types of angle

Questions Related to types of angle

The difference between two angles is $19$$\displaystyle ^{o}$ and their sum is $\displaystyle \frac{890}{9}^o$. Find the greater angle.

  1. $63^o$

  2. $35^o$

  3. $27^o$

  4. $59^o$


Correct Option: D
Explanation:
Let the two angles be $a$ and $b$

Then, 
$a  - b = 19$

and, $a + b = \dfrac{890}{9}$

Adding the two equations,

$2a = \dfrac{890 + 19\times 9}{9}$

$2a = \dfrac{1061}{9}$

Thus, $a = \dfrac{1061}{18}$

$a \approx 59^{\circ}$

If two angles of a triangle are acute angles, the third angle:

  1. is less than the sum of the two angles

  2. is an acute angle

  3. is the largest angle of the triangle

  4. may be an obtuse angle


Correct Option: D
Explanation:
For a triangle $ABC$, sum of angles is $180^0$
Two angles are given as acute, $\angle A, \angle B < 90^0$
$\angle A = 90^0 - x$
$\angle B = 90^0 - y$
where, $x,y < 90^0$
$\therefore \angle A + \angle B+ \angle C = 180^0$
$\Rightarrow \angle C = x+y $
$x+y$ can be $>90^0$ or $<90^0$
So, it may be obtuse or acute.
Hence, option D.

An angle which measures $\displaystyle 0^{o}$ is called:

  1. obtuse angle

  2. straight angle

  3. zero angle

  4. right angle


Correct Option: C
Explanation:

An angle which measure $0^0$ is called zero angle.

An angle which measure more than $0^o$ and less than $90^o$ is an acute angle.
An angle which measures $90^o$ is called a right angle.
An angle which measure more than $90^o$ and less than $180^o$ is an obtuse angle.

Hence, the answer is zero angle.

Find the supplement  of the following angle.
$40^{\circ}$

  1. $140$

  2. $40$

  3. $10$

  4. None of these


Correct Option: A
Explanation:

We know that the supplement angle

$=180^0-\theta$

So,
The supplement angle of $40^0$ will be
$=180^0-40^0=140^0$ 

Hence, this is the answer.

Say True or False.
The measure of an obtuse angle $< 90^o$.

  1. True

  2. False


Correct Option: B
Explanation:

False
The measure of an obtuse angle is greater than $90^o$ but less than $180^o$.

An angle whose measure is the sum of the measures of two right angles is _______.

  1. Acute

  2. Obtuse

  3. Right

  4. Straight


Correct Option: D
Explanation:

Measure of a right angle is $90^ \circ$

Measure of a straight angle is $180^ \circ$
Sum of the measure of two right angles is $(90+90)^ \circ=180^ \circ$
Thus an angle whose measure is the sum of two right angles is $Straight$

An angle whose measure is greater than that of a right angle is ______.

  1. Acute

  2. Obtuse

  3. Right

  4. Straight


Correct Option: B
Explanation:

$Obtuse \ angle$ has measure more than that of $right \ angle \ but \ less \ than \ 180\ degree$

Hence correct answer is $B) \ Obtuse$

An angle whose measure is less than that of a right angle is ______.

  1. Acute

  2. Obtuse

  3. Right

  4. Straight


Correct Option: A
Explanation:

$Acute \ angle$ has measure less than $right \ angle$

Hence correct answer is $A) \ Acute$

$\displaystyle 89^{\circ}$ is an example of :

  1. obtuse

  2. acute

  3. right

  4. None of the above


Correct Option: B
Explanation:

Angles between $ {0}^{o} $ and $ {90}^{o} $ are acute angles. Hence, $ {89}^{o} $ is an acute angle.

Based on the angle measures given, which triangle is not acute?

  1. $35^\circ,\, 69^\circ,\, 76^\circ$

  2. $60^\circ,\, 60^\circ,\, 60^\circ$

  3. $88^\circ,\, 46^\circ,\, 46^\circ$

  4. $90^\circ,\, 45^\circ,\, 45^\circ$


Correct Option: D
Explanation:

For acute angles triangle all the three angles must be less than ${ 90 }^{ \circ  }$.

In option $D$ one of the angle is ${ 90 }^{ \circ  }$ , so it is not acute angles triangle.