Question 1129877
0.5in and 2in are both possible.<br>

For a proper triangle with sides x,y,z,  the triangle inequalities must hold:  z < x+y,  x < y+z, y < x+z <br>

0in is the degenerate case where one side has zero length (so it collapses to a line, and is not a proper triangle).  Also {{{ 0 + 15.7/2 }}} &#x226F; {{{ 15.7/2 }}} <br>

7.9in is too long for b, as the other sides will be (15.7-7.9)/2 = 3.9in and it won't form a closed figure.  Notice {{{ 3.9 + 3.9 }}} &#x226F; {{{ 7.9 }}} <br>

-2in is nonsensical, a >0, b>0 must be true.