Question

2
In the triangle PQR, PQ = 2a bar and QR = 2b bar The mid-point of PR is M. Find following
vectors in terms of a bar and b bar
(i) PR bar
(ii) PM bar
(iii) QM bar​

Answer 1

Answer:

Draw the figure and mark the point on it. <br> ii) Join BQ, now BQ is the median to PR. Since PQ=QR, BQ is also the altitude to PR. <br> iii) PBQ is a right triangle, right angled at B. Thus, PQ is the diameter. <br> iv) Joining PA, we get another right triangle PAQ which is right angled at A. PBQ and PAQ are congruent angles. <br> iv) PR=QR, so

is an equilateral triangle.