The given triangles are similar Fundy length of XAX equals 20BX equals 15C.X equals two or d x equals six

Given that the triangles are similar, we can set up a proportion to find the value of x:

\( \frac{AX}{BX} = \frac{CX}{X} \)

Substitute the given values:

\( \frac{20}{15} = \frac{C}{6} \)

\( \frac{4}{3} = \frac{C}{6} \)

Cross multiply to solve for C:

\( 4 \times 6 = 3 \times C \)

\( 24 = 3C \)

\( C = 8 \)

Therefore, the value of C is 8.