Step-by-step explanation:
it is not clear, if RT = 20 or UT = 20.
both are possible scenarios.
I assume that RT = 20 (otherwise the sub-triangle RSU is not sufficiently defined, as R could be moved outward to the left it further inward to the right, and the rest of the triangle is unchanged).
for any triangle with sides a, b, c and semiperimeter
s = (a + b + c) / 2, the height to side a is
ha = 2×sqrt(s(s-a)(s-b)(s-c))/a
in our case here
s = (20+25+17)/2 = 62/2 = 31
hRT = SU = 2×sqrt(31×(31-20)(31-25)(31-17))/20 =
= sqrt(31×11×6×14)/10 = sqrt(28,644.)/10 =
= 16.9245384...
RU² = 17² -SU² = 289 - 286.44 = 2.56
RU = 1.6 ≈ 2
