Question 979474


The perimeter of a triangle is 

{{{P=a + b + c}}}, 

if Billy tells us that the perimeter of a particular triangle is {{{P=30cm}}},{{{ a=25cm}}} and {{{b=10cm}}}, than

{{{30cm=25cm+ 10cm + c}}}

{{{30cm=35cm + c}}}
 
since already {{{30cm<25cm+ 10cm}}}, we know that {{{c=-5cm}}} and the sides of the triangle could not be negative number

so, Billy  gave us wrong data