By most definitions, if the bases are congruent, it is not a trapezoid, it is a parallelogram.
3x+4 combine like terms I think lol
We have from Thales theorem that because the 2 triangles are similar, JM/JK=JN/JL. We have that JN=x, JL=x+24 and that JM=7 and JK=28. Substituting, we get:
x/(x+24)=7/28.
Hence, x/(x+24)=1/4. This leads to 4x=x+24, 3x=24, x=8. We have solved for x=JN and this is equal to 8.
Check the picture below.
so.. notice, the box for the gift is really just a rectangular prism, which is really just 6 rectangles stacked up to each other at the edges.
the front and back are two 5x3 rectangles
the left and right are just two 3x7 rectangles
and the top and bottom are just two 5x7 rectangles
so, just get the area of each, sum them up, and that's the area of the rectangular prism and thus of the box, and that's how many in² she will need.
I believe this is how you do it