Question 113053

your figure has 12 sides in all

the perimeter {{{P}}} of a polygon is the distance around the outside of the polygon; means add up the length of all sides

so,
{{{P = 1.4cm + 6(2.1cm) + 3(2.8cm) + 2(3.5cm)= 1.4cm + 12.6cm + 8.4cm + 7cm =29.4cm}}}