Find the value of c using the diagram below

Check the picture below.

notice that 146° is sitting on a flat-line, and thus it has a sibling linear angle, namely 34°.

now, recalling that a triangle has a sum of 180° for all interior angles, the missing one is 126°, and incidentally that is a corresponding angle with "c".

to solve, set up an expression

120 (0.25)

now, simply multiply

the item is now $30