Let A be (3,5) and B be (5,10)). Find: (1) the length of segment ¯¯¯¯¯¯AB (2) the midpoint P of ¯¯¯¯¯¯AB (3) the point Q which splits ¯¯¯¯¯¯AB in the ratio 2:5?

1 Answer
Mar 1, 2017

(1) the length of the segment ¯¯¯¯¯¯AB is 17
(2) Midpoint of ¯¯¯¯¯¯AB is (1,712)
(3) The coordinates of the point Q which splits ¯¯¯¯¯¯AB in the ratio 2:5 are (57,57)

Explanation:

If we have two points A(x1,y1) and B(x2,y2), length of ¯¯¯¯¯¯AB i.e. distance between them is given by

(x2x1)2+(x2x1)2

and coordinates of the point P that divides the segment ¯¯¯¯¯¯AB joining these two points in the ratio l:m are

(lx2+mx1l+m,lx2+mx1l+m)

and as midpoint divided segment in ratio 1:1, its coordinated would be (x2+x12,x2+x12)

As we have A(3,5) and B(5,10)

(1) the length of the segment ¯¯¯¯¯¯AB is

(5(3))2+((10)5)2

= 82+(15)2=65+225=289=17

(2) Midpoint of ¯¯¯¯¯¯AB is (532,1052) or (1,712)

(3) The coordinates of the point Q which splits ¯¯¯¯¯¯AB in the ratio 2:5 are

(2×5+5×(3)7,2×(10)+5×57) or (10157,20+257)

i.e. (57,57)