In this task, you need to answer the given multiple-choice question on geometry. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.
Example: Problem: if the sides of a triangle are 20 cm , 12 cm and 16 cm , what is its area ? 
Options: a ) 70 , b ) 79 , c ) 85 , d ) 96 , e ) 92
Example solution: d
Example explanation: "Based on the pythagorean theorem, the triangle with sides 20 cm, 12 cm and 16 cm is right angled, where the hypotenuse is 20 cm. area of the triangle = 1 / 2 * 12 * 16 = 96 cm 2 answer : option d"

Problem: Problem: the area of a triangle will be when a = 1 m , b = 4 m , c = 5 m , a , b , c being lengths of respective sides ? 
Options: a ) 2 , b ) 7 , c ) 5 , d ) 3 , e ) 4

Solution: c