## Lecture-3

00:00:48 NCERT Exercise 6.2 Question 2 E and F are points on the sides PQ and PR respectively of a ∆ PQR. For each of the following cases, state whether EF || QR : (i) PE = 3.9 cm, EQ = 3 cm, PF = 3.6 cm and FR = 2.4 cm (ii) PE = 4 cm, QE = 4.5 cm, PF = 8 cm and RF = 9 cm (iii) PQ = 1.28 cm, PR = 2.56 cm, PE = 0.18 cm and PF = 0.36 cm

00:08:48 NCERT Exercise 6.2 Question 3 In Fig. 6.18, if LM || CB and LN || CD, prove that AM/AB=AN/AD

00:18:28 NCERT Exercise 6.2 Question 4 In Fig. 6.19, DE || AC and DF || AE. Prove that BF/BE=FE/EC

00:23:18 NCERT Exercise 6.2 Question 5 In Fig. 6.20, DE || OQ and DF || OR. Show that EF || QR.

00:28:38 NCERT Exercise 6.2 Question 6 In Fig. 6.21, A, B and C are points on OP, OQ and OR respectively such that AB || PQ and AC || PR. Show that BC || QR.

00:32:30 NCERT Exercise 6.2 Question 7 Using Theorem 6.1, prove that a line drawn through the mid-point of one side of a triangle parallel to another side bisects the third side. (Recall that you have proved it in Class IX).

00:36:48 NCERT Exercise 6.2 Question 8 Using Theorem 6.2, prove that the line joining the mid-points of any two sides of a triangle is parallel to the third side. (Recall that you have done it in Class IX).