Given the task definition and input, reply with output. In this task, you need to answer the given multiple-choice question on geometry. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Problem: there is a right angle triangle inside a circle of diameter 18 cm . inside this triangle , there is another circle of diameter 6 cm . find the perimeter of the triangle .
Options: ['a ) 24 cm', 'b ) 36 * 2 ^ 1 / 2 cm', 'c ) 36 cm', 'd ) 54 cm', 'e ) 42 cm']
e