Step-by-step explanation:
something is missing here.
it is not clear, what exactly is 27 km. only the side of the orange triangle ? or the whole distance to the 90 degree angle ?
but in both cases that is not enough. we need some information about the split ratio of the orange side and the white side. it some angles in the graphic.
otherwise I can simply keep the given sides with their lengths but freely move the line between the orange and white triangles. there are infinite many solutions.
is it meant to be an isoceles triangle (2 equal sides) ? it certainly does not look like it, but that would be the only case where the given information can lead to a solution.
under that assumption the baseline of the white triangle is also 27 km.
the first side is 9km.
the second side we get via Pythagoras :
27² = 9² + x²
729 = 81 + x²
648 = x²
x = 25.46 km
now, since this is a right-angled triangle we can (especially to calculate the area) also consider the two sides enclosing the 90 degree angle as baseline and height.
the area of a triangle is baseline×height/2
area = 9×25.46/2 = 114.55 km²
