Question 547202
Yes, it's possible.  The reason you know is because the sum of any
two sides is greater than the third side:

5+7 > 8  because 12 is greater than 8

5+8 > 7  because 13 is greater than 7

7+8 > 5  because 15 is greater than 5.

Here it is drawn below:
The left side is 5, the bottom side is 7,
and the right side is 8.  (Count the spaces between 
the little round marks).

{{{drawing(400,2800/9,-1,8,-1,6,

circle((.1428571429),(.9897433186),.1),
circle(2(.1428571429),2(.9897433186),.1),
circle(3(.1428571429),3(.9897433186),.1),
circle(4(.1428571429),4(.9897433186),.1),
circle(5(.1428571429),5(.9897433186),.1),
circle(0,0,.1),
circle(1,0,.1),
circle(2,0,.1),
circle(3,0,.1),
circle(4,0,.1),
circle(5,0,.1),
circle(6,0,.1),
circle(7,0,.1),

circle(7-1(.7857142857), 1(.6185895741),.1),
circle(7-2(.7857142857), 2(.6185895741),.1),
circle(7-3(.7857142857), 3(.6185895741),.1),
circle(7-4(.7857142857), 4(.6185895741),.1),
circle(7-5(.7857142857), 5(.6185895741),.1),
circle(7-6(.7857142857), 6(.6185895741),.1),
circle(7-7(.7857142857), 7(.6185895741),.1),
circle(7-8(.7857142857), 8(.6185895741),.1),
green(triangle(0,0,5(.1428571429),5(.9897433186),7,0)) )}}}


Edwin</pre>