Question 601539
The front of the tent would look like this:
{{{drawing(300,300,-4,4,-2.5,5.5,
triangle(-3,0,3,0,0,4), line(0,0,0,4),
locate(-1.5,0.4,3), locate(1.5,0.4,3),locate(0,2.5,4)
)}}} made of 2 right triangles with leg lengths of 3 feet and 4 feet.
The area of each triangle (in square feet) is
{{{(1/2)*3*4=6}}} so the front requires at least 12 square feet of canvas.
The back will also require 12 square feet of canvas.
The hypotenuse of those right triangles has a length (in feet) of {{{x}}} and
{{{x^2=3^2+4^2=9+16=23}}} according to Pythagoras theorem.
So {{{x=sqrt(23)}}} or about 4.8 feet.
The pieces that form the roof will have that width and a length of 9 feet.
So the amount of canvas needed for the roof (in square feet) is
{{{2*(sqrt(23)*9)=2*9*sqrt(23)=18*sqrt(23)}}}
That must be added to the
{{{2*12)}}} square feet of canvas = 24 square feet of canvas for front and back.
For the mathematically exact answer, you will need
{{{24+18*sqrt(23)}}} square feet of canvas (about 110.325 square feet of canvas).
Of course, the practical answer will be that you need more for seams and flaps, and whatnot.