Q: 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: a lamp is put on one corner of a square plot of side 50 m . it ' s light reaches 21 m . find the area of that plot that is lit by that lamp ?
Options: ['a ) 248', 'b ) 312.5', 'c ) 346.5', 'd ) 392.5', 'e ) 424']
A:
c