Draw a pair of vertically opposite angles. Bisect each of the two angles. Verify that the bisecting rays are in the same line.

Draw a liner pair of angles. Bisect each of the two angles. Verify that the two bisecting rays are perpendicular to each other.

Draw a linear pair of angles. Bisect each of the two angles. Verify that the two bisecting rays are perpendicular to each other.

Draw an obtuse angle. Bisect it. Measure each of the angles so obtained.

Prove that the bisectors of a pair of vertically opposite angles are in the same straight line.

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 areacute angles, then the other pair of vertically opposite angles are __________.

Show that the diagonals of a rhombus bisect each other at right angles.

If two straight lines intersect each other, prove that the ray opposite to the bisector of one of the angles thus formed bisects the vertically opposite angle.

Prove that :The diagonals of a rhombus bisect each other at right angle.

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 sameside of the transversal.(iv) the vertically opposite angles.

Show that the bisector of vertical angle of an isosceles triangle bisects the base at right angles.