**Chapter 1 Basic Concepts in Geometry Practice Set 1.3**

Chapter 1 Basic Concepts in Geometry Practice Set 1.3

**Question 1.Write the following statements in ‘if-then’ form.i. The opposite angles of a parallelogram are congruent.ii. The diagonals of a rectangle are congruent.iii. In an isosceles triangle, the segment joining the vertex and the midpoint of the base is perpendicular to the base.Answer:**

i. If a quadrilateral is a parallelogram, then its opposite angles are congruent.

ii. If a quadrilateral is a rectangle, then its diagonals are congruent.

iii. If a triangle is isosceles triangle, then segment joining the vertex of a triangle and midpoint of the base is perpendicular to the base.

**Question 2.Write converses of the following statements.i. The alternate angles formed by two parallel lines and their transversal are congruent.ii. If a pair of the interior angles made by a transversal of two lines are supplementary, then the lines are parallel.iii. The diagonals of a rectangle are congruent.Answer:**
i. If the alternate angles made by two lines and their transversal are congruent, then the two lines are parallel.

ii. If two parallel lines are intersected by a transversal, then the interior angles formed bv the transversal are supplementary.

iii. If the diagonals of a quadrilateral are congruent, then that quadrilateral is a rectangle.