Question 16 (OR 1 st question)

The points A(1, –2) , B(2, 3), C (k, 2) and D(–4, –3) are the vertices of a parallelogram. Find the value of k.

The points A(1, -2) , B(2, 3), C (k, 2) and D(-4, -3) are vertices of

Question 16 (Or 1st) - CBSE Class 10 Sample Paper for 2019 Boards - Part 2
Question 16 (Or 1st) - CBSE Class 10 Sample Paper for 2019 Boards - Part 3
Question 16 (Or 1st) - CBSE Class 10 Sample Paper for 2019 Boards - Part 4

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Question 16 (OR 1st question) The points A(1, –2) , B(2, 3), C (k, 2) and D(–4, –3) are the vertices of a parallelogram. Find the value of k. Let’s first draw the figure We know that Diagonals of parallelogram bisect each other So, O is mid-point of AC & O is mid-point of BD 1 mark Finding mid−point of AC We have to find x coordinate of O x−coordinate of O = (𝑥1 + 𝑥2)/2 Where x1 = 1 , x2 = k Putting values x−coordinate of O = (1 + 𝑘)/2 = (𝑘 + 1)/2 1/2 mark Finding mid−point of BD We have to find x coordinate of O x−coordinate of O = (𝑥1 + 𝑥2)/2 Where x1 = 2 , x2 = –4, Putting values for x−coordinate x−coordinate of O = (2 + (−4))/2 = (−2)/2 = –1 …(2) 1/2 mark Comparing (1) & (2) (𝑘 + 1)/2 = –1 k + 1 = –1 × 2 k + 1 = –2 k = –2 – 1 k = – (2 + 1) k = –3 Hence, k = –3 1 mark

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Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo