help me help me. i don understand
I found a way to get an answer in terms of r, but I am not sure that we shouldn't be able to deduce r somehow and I suspect Earboth knows what I'm about to post already, but just in case:
Angles marked the same are the same because of congruent triangles.
$\displaystyle 2\times +2\circ+2\square = 2\pi$
$\displaystyle \times+\circ+\square = \pi$
$\displaystyle \tan(\times) = 25/r$
$\displaystyle \tan(\circ) = 12/r$
$\displaystyle
\tan(\square) = \tan(\pi-\circ-\times)$
$\displaystyle =-\tan(\circ+\times)$
$\displaystyle
=-\frac{(25/r)+(12/r)}{1-300/r^2}$
$\displaystyle =\frac{37r}{300-r^2}$
If P is the midpoint of BC then PB = 12 too and - most important - RB = 12 for symmetry reasons.
You now can determine the lengths of all sides:
AC= 25 + 12 = 37
BC = 12 + 12 = 24
AB = 25 + 12 = 37
That means you are dealing with an isosceles triangle with base BC = 24