Instructions: In this task, you need to answer the given multiple-choice question on geometry. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.
Input: Problem: if the sides of a triangle are 30 cm , 28 cm and 10 cm , what is its area ? 
Options: a ) 120 , b ) 110 , c ) 130 , d ) 140 , e ) 150
Output:
d