Question 980905
Hi there,
First consider the perpendicular
height divides the isosceles into
two right angled triangles back
to back.
We are given the height = 1.5 ft
We are given the base = f so we 
divide it by 2 and this gives
the size of the base of the right
angled triangle f/2
To find the hypotenuse we must
sqrt (f/2)^2 + (1.5)^2
= sqrt f^2/4 + 2.25
So the braid to go round the rug
will == 2(sqrt(f^2/4 + 2.25)) + f
Hope this helps:-)