Given a line ABCD in which AB = BC = CD, B= (0, 3) and C= (1, 8). Find the co-ordinates of A and D.
Equation of line BC is
y=5x+3
BC = √(0−1)2+(3−8)2 = √26
let the coordinates of A is x1, y1
then from distance formula AB=BC
We had
x12+(y1−3)2= 26
solving this with equation of line we get x1=-1 and y1=-2
(-1, -2)
similarly
for point D let co-ordinated are x2, y2
(x2−1)2+(y2−8)2=26
substituting y2 from equation of line
we get
(x2−1)2=1
fro this x2 =2
and from equation of line y2=13
(2,13)