Question 1005911
In parallelogram {{{ABCD}}} ,
{{{AD}}} is one side;
{{{AC}}} and {{{BD}}} are diagonals.
The diagonals of a parllelogram bisect each other,
meaning that {{{AC}}} and {{{BD}}} intersect
at a point {{{M}}} that is the midpoint of {{{AC}}} and {{{BD}}} .
So, {{{AM=(1/2)AC=6.8cm/2=3.4cm}}} and
{{{DM=(1/2)DB=7.6cm/2=3.8cm}}} .
Let us draw {{{AD}}} , and find {{{M}}} .
To find {{{M}}} , we draw arcs of the circles
centered at A with radius {{{AM=3.4cm}}} , and
centered at D with radius {{{DM=3.8cm}}} .
Where those two arcs meet, we find {{{M}}} .
{{{drawing(300,180,-2,8,-1,5,
line(0,0,6.4,0),locate(-.2,0,A),
locate(6.3,0,D),locate(2.7,0,6.4cm),
red(arc(0,0,6.8,6.8,-70,-10)),
red(arc(6.4,0,7.6,7.6,-170,-120)),
red(arrow(0,0,1.7,2.944)),locate(0.85,1.472,red(3.4cm)),
red(arrow(6.4,0,3.713,2.687)),locate(5,1.8,red(3.8cm)),
circle(2.975,1.646,0.18),locate(2.875,2.2,M)
)}}}
Now, let us draw
ray {{{AM}}} , with point {{{C}}} , and
ray {{{DM}}}  , with point {{{B}}} .
After that, we just connect points,
{{{A}}} to {{{B}}} ,
{{{B}}} to {{{C}}} , and
{{{C}}} to {{{D}}} ,
to complete the parallelogram.
{{{drawing(300,180,-2,8,-1,5,
line(0,0,6.4,0),locate(-.2,0,A),
locate(6.3,0,D),locate(2.7,0,6.4cm),
circle(2.975,1.646,0.18),locate(2.875,2.2,M),
green(arrow(0,0,6.545,3.621)),
green(arrow(6.4,0,-1.135,3.621)),
circle(-0.45,3.292,0.18),locate(-0.55,3.9,B),
circle(5.95,3.292,0.18),locate(5.85,3.9,C),
locate(4.69,1.3,green(3.8cm)),locate(1.26,2.97,green(3.8cm)),
locate(4.46,2.47,green(3.4cm)),locate(1.49,0.82,green(3.4cm)),
line(-0.45,3.292,5.95,3.292),line(0,0,-0.45,3.292),line(6.4,0,5.95,3.292)
)}}}