Question 1153567
The lengths of two sides of a triangle of {{{8ft}}} and {{{12ft}}}. 

What are the possible lengths for a third side?

the sum of any {{{2}}} sides of a triangle must be greater than the measure of the third side

{{{8ft+12ft=20ft}}}

Denoting the third side as {{{s}}}:

{{{8+12>s}}}
{{{s<20}}}.....eq.1


Also,

{{{8+s>12}}}
{{{s>12-8}}}
{{{s>4}}}.....eq.1

and

{{{12+s>8}}}
{{{s>8-12}}}
{{{s>-4}}}.....eq.1 disregard negative number

from eq.1 and eq.2, we  have  {{{4<s<20}}}

A) 3ft-> {{{NOT}}} the possible length for a third side
B) 5ft->the possible length for a third side
C) 21ft-> {{{NOT}}} the possible lengths for a third side
D) 15ft->the possible lengths for a third side
E) 18ft->the possible lengths for a third side
F) 9ft-> the possible lengths for a third side