Question

if two sides of a triangle are of lengths 7 cm and 13cm, then the third side must be.

Answer 1

$7+13= 20cm$

$13-7=6cm$

$length\:of\:third\:side\:must\:be\:smaller\:than\:20cm\:and\:greater\:than\:6cm$

Answer 2

The thrid side must belong to open inteval (6,20)