In Fig.15, write down: (i) each linear pair (ii) each pair of vertically opposite angles.

In Fig (5.18) identify: (i) Five pairs of adjacent angles.( ii) Three linear pairs.(iii) Two pairs of vertically opposite angles

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 __________.

In each of the following figures, write, if any, (i) each pair of vertically opposite angles, and (ii) each linear pair.

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 ( iv) Adjacent angles that do not form a linear pair

In Fig.14, name all the pairs of adjacent angles.

Point OF angle || Adjacent angle || Linear pair OF angle || Vertical-opposite angle|| Transversal lines Corresponding angle|| Alternate Interior angle || Co-interior|| Exterior angle || Example discussion

Indicate which pairs of angles are: (i) Vertically opposite angles.(ii) Linear pairs.

Draw a quadrilateral XYZW and name the pairs of opposite angles.

In the adjoining figure,identify ( i ) the pairs of corresponding angles.(ii) the pairs of alternate interior angles.(iii) the pairs of interior angles on the same side of the transversal.(iv) the vertically opposite angles.