Question 1070634
If point A(6,1),B (8,2),C (8,4),D (p,3) are vertices of a parallelogram taken in order, find value of p
<pre><b><font face = “Century Gothic” size = 4 color = "indigo">AB &#8741 DC and BC &#8741 AD
BC is a VERTICAL line that's parallel to the y-axis, and parallel and congruent to AD. BC's length = 4 - 2, or 2
AD is a VERTICAL line that's parallel to the y-axis, and parallel and congruent to BC. Points A and D will therefore have the SAME x-coordinate, which is 6.
Therefore, p = 6.

<u>OR</u>

You can also see that AB and DC are parallel, and so, have the same slope. Slope of AB = {{{matrix(1,5, (1 - 2)/(6 - 8), or, (- 1)/(- 2), or, 1/2)}}}
DC's slope also = {{{1/2}}}. 
To find p, we get: {{{matrix(1,17, (3 - 4)/(p - 8), "=", 1/2, "=====>", (- 1)/(p - 8), "=", 1/2, "=====>", p - 8, "=", - 2, "=====>", p, "=", - 2 + 8, or, 6)}}}</font></b></pre>