In a △ABC, AB = 6 cm, BC = 7 cm and CA = 8 cm. The smallest angle of the triangle is :

1. ∠A

2. ∠B

3. ∠C

4. None of these

In a △ABC, 2∠A = 3∠B and ∠C = 100°. The correct ascending order of sides of the triangle is :

1. AC < BC < AB

2. BC < AC < AB

3. AB < AC < AB

4. BC < AB < AC

In △ABC, AB > AC and D is any point on BC, then, AB is :

1. < DC

2. < AD

3. = BC

4. > AD

Case Study

Ms Anu Gupta teaches mathematics to class 9 in a school. One day she drew a figure on the board in the class. She provided the following clues to the students.

AB || CD

O is the mid-points of AD

Based on this information, answer the following questions:

1. △OAB ≅ △ODC by which of the following congruent condition?
   (a) SAS
   (b) ASA
   (c) SSS
   (d) RHS

2. ∠AOB = ∠DOC holds because:
   (a) Alternate angles are equal
   (b) Corresponding angles are equal
   (c) Vertically opposite angles are equal
   (d) None of these

3. Which of the following is correct?
   (a) ∠A = ∠C
   (b) ∠B = ∠D
   (c) ∠B = ∠C
   (d) ∠AOB = ∠OCB

4. Which of the following is correct?
   (a) AO = OB
   (b) AB = OB
   (c) OD = CD
   (d) OC = OB

5. Which of the following is not a congruent condition?
   (a) ASA
   (b) SSS
   (c) AAA
   (d) AAS