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