Question

Three vertices of parallelogram WZXY are W(-5, 2), X(2, 4) and Z(-7, -3). Find the coordinated of the vertex, Y.

Answer 1

Answer:

$Y = (4,9)$

Step-by-step explanation:

Given

$W(x_1,y_1) = (-5, 2)$

$Z(x_4,y_4) = (-7, -3)$

$X(x_2,y_2) = (2, 4)$

Required

Find Y

To do this, we make use of the mid-point formula

i.e.

$M = \frac{1}{2}(x_n+x_m,y_n+y_m})$

WX and ZY are the diagonals of the parallelogram.

The mid-point of WX is:

$M = \frac{1}{2}(-5+2,2+4)$

$M = \frac{1}{2}(-3,6)$

The mid-point of ZY is:

$M = \frac{1}{2}(-7+x,-3+y)$

Equate both values of M

$\frac{1}{2}(-3,6) = \frac{1}{2}(-7+x,-3+y)$

Multiply both sides by 2

$(-3,6) = (-7+x,-3+y)$

By comparison:

$-7 + x = -3$

$-3 + y = 6$

$-7 + x = -3$

$x = 7 -3$

$x = 4$

$-3 + y = 6$

$y = 6 +3$

$y = 9$

Hence:

$Y = (4,9)$