**14. **In the adjoining figure, name the following pairs of angles.

**(i)** Obtuse vertically opposite angles

** (ii)** Adjacent complementary angles

** (iii)** Equal supplementary angles

**(iv)** Unequal supplementary angles

**(v)** Adjacent angles that do not form a linear pair

(i) are the vertically obtuse angles.
(ii) are the complementary angles.
(iii) are the equal supplementary angles.
(iv) are the unequal pair of supplementary angle.
(v) , and are adjacent angles but are not supplementary angles.

**13. **Fill in the blanks:** **

** (i)** If two angles are complementary, then the sum of their measures is _______.

** (ii)** If two angles are supplementary, then the sum of their measures is ______.

** (iii)** Two angles forming a linear pair are _______________.

**(iv) **If two adjacent angles are supplementary, they form a ___________.

**(v)** If two lines intersect at a point, then the vertically opposite angles are always _____________.

**(vi)** If two lines intersect at a point, and if one pair of vertically opposite angles are acute angles, then the other pair of vertically opposite angles are __________.

(i)
(ii)
(iii) Supplementary angles
(iv) Straight line
(v) equal
(vi) obtuse angles (as they form a line).

**12.(ii) **Find the values of the angles x, y, and z in each of the following:** **

** **

From the figure we can observe that :
(i) (Vertically opposite angle)
(ii) (Linear pair/straight line)
(iii) (Vertically opposite angle).

**12.(i) **Find the values of the angles x, y, and z in each of the following:

From the figure :
(i) (Vertically opposite angle)
(ii) (Linear pair)
(iii) (Vertically opposite angle)

**10.(ii)** Indicate which pairs of angles are:

**(ii)** Linear pairs

**10.(i)** Indicate which pairs of angles are:

** (i)** Vertically opposite angles.

**11. **In the following figure, is adjacent to ? Give reasons.

No, and are not adjacent angles as their vertex is not same/common.
For being adjacent angles the pair must have a common vertex and have a common arm.

**9.** In the adjoining figure:

(i) Is adjacent to ?

(ii) Is adjacent to ?

(iii) Do and form a linear pair?

(iv) Are and supplementary?

(v) Is vertically opposite to ?

(vi) What is the vertically opposite angle of ?

(i) Yes, adjacent to as these have the same vertex and have one common arm.
(ii) No, is not adjacent to . This is because contains .
(iii) Yes the given angles form a linear pair as they are pair of supplementary angles.
(iv) Since BOA is a straight line thus the given angles are supplementary.
(v) Yes, and are vertically opposite angles as they are the angles formed by two intersecting...

**8. **An angle is greater than . Is its complementary angle greater than or equal to or less than ?

We know that the sum of two complementary angles is .
Thus if one of the angles is greater than then the other angle needs to be less than .

**7. **Can two angles be supplementary if both of them are:

(i) acute ? (ii) obtuse ? (iii) right ?

We know that the sum of supplementary angles is .
(i) The maximum value of the sum of two acute angles is less than . Thus two acute angles can never be supplementary.
(ii) The minimum value of the sum of two obtuse angles is more than . Thus two obtuse angles can never be supplementary.
(iii) Sum of two right angles is . Hence two right angles are supplementary.

**6. **In the given figure, and are supplementary angles. If is decreased, what changes should take place in so that both the angles still remain supplementary.** **

** **

Since it is given that and are supplementary angles, i.e. the sum of both angles is .
Thus if is decreased then to maintain the sum needs to be increased.

**5. **Find the angle which is equal to its supplement.** **

**4. **Find the angle which is equal to its complement.

**3. **Identify which of the following pairs of angles are complementary and which are supplementary.

We know that the sum of supplementary angles is and the sum of complementary angle is .
(i) Sum of the angles is : . Hence these are supplementary angles.
(ii) Sum of the angles is : . Hence these are complementary angles.
(iii) Sum of the angles is : . Hence these are supplementary angles.
(iv) Sum of the angles is : . Hence these are supplementary angles.
(v) Sum of the angles...

**2.(iii) **Find the supplement of each of the following angles:

We know that the sum of angles of supplementary pair is .
Thus the supplement of the given angle is :

**2.(ii) **Find the supplement of each of the following angles:

**2.(i) **Find the supplement of each of the following angles:

**1.(iii) **Find the complement of each of the following angles:

**1.(ii) **Find the complement of each of the following angles:

The sum of the complementary angle is .
Thus the complementary angle to the given angle is :

**1.(i) **Find the complement of each of the following angles:

Exams

Articles

Questions