## Maharashtra State Board Class 9 Maths Solutions 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.