Question

can someone please help ill try to add the picture

Answer 1

check the picture below.

the lateral area, namely the area of the sides, is just the area of 4 rectangles.

left and right, 4x3 rectangles,

front and back, 15x3 rectangles,

so the lateral area of the box is just the sum of those areas,

 $\bf \stackrel{\textit{left and right}}{(4\cdot 3)}~~~~+~~~~\stackrel{\textit{front and back}}{(15\cdot 3)}$