Step-by-step explanation:
the area of a triangle is
baseline × height / 2
now we also know that
the height in that triangle is twice its baseline.
so,
height = 2×baseline
so, for the given area we have
49 = baseline × 2 × baseline / 2 = baseline²
baseline = 7 ft.
therefore,
height = 2×baseline = 2×7 = 14 ft.
and now we run into a problem. as we don't have any further information about the triangle, the lengths of the sides cannot be determined.
the reason is that the height can be placed anywhere on the baseline (from the left end point all the way over to the right end point). all these triangles created by the moving height have the same area (49 ft²), but different lengths of the legs.
the lengths of the legs are calculated via Pythagoras, because the height splits the main triangle into 2 smaller right-angled triangles.
so, if I assume e.g. an isoceles triangle (both legs are equally long), then I know that the height splits the triangle into 2 equal triangles and the baseline in half.
then I can calculate :
leg² = (baseline/2)² + height² = 3.5² + 14² =
= 12.25 + 196 = 208.25
(each) leg = 14.43086969... ft
if I assume the height is at an endpoint of the baseline then the whole triangle is by itself a right-angled triangle.
and the height is one leg and the other leg is again via Pythagoras
leg² = baseline² + height² = 7² + 14² = 49 + 196 = 245
leg = 15.65247584... ft
all the possible solutions for the leg lengths are between 14 ft (the height) and 15.65247584... ft.