Write in conditional form:
(i) Every rhombus is a square.
(ii) Interior angles are supplementary to each other.

State whether the statements are True or False. Two right angles are always supplementary to each other.

Each interior angle of a regular decagon is

The measure of each interior angle of a regular octagon is

Write the following statement in conditional form : Angles in a linear pair are supplementary .

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 __________.

The diagonals of a rhombus are perpendicular to each other.

Two straight lines are cut by a transversal. If the bisectors of a pair of co-interior angles are perpendicular to each other , prove the two straight lines are parallel to each other.

Two angles are in the ratio 4:5 Find the angles if they are (i) complementary (ii) supplementary to each other.

If a transversal intersects two lines in such a way that a pair of consecuitive interior angles are supplementary; then two lines are parallel.

The properties of a rhombus can be summarized as under: (i) All the sides of a rhombus are equal.(ii) The opposite angles of a rhombus are equal.(ii) The opposite angles of a rhombus are supplementary.(iv) The diagonals of a rhombus bisect each other at right angles.