This is an impossible figure.....to see why
Draw perpendicular TS to base XY.....
Now triangle XTS is right with angle TSX = 90°
And SX = ( 40 -12 ) / 2 = 14
But XT is the hypotenuse of triangle XTS = 7 and SX and TS are legs
But this means that leg SX is actually longer than hypotenuse TX which is impossible