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

[Q]: Problem: find the area of a rhombus one side of which measures 20 cm and one diagonal is 28 cm .
Options: ['a ) 200 cm 2', 'b ) 300 cm 2', 'c ) 400 cm 2', 'd ) 448 cm 2', 'e ) 100 cm 2']
[A]: d

[Q]: Problem: in the xy - plane , a triangle has vertices ( 0,0 ) , ( 4,0 ) and ( 4,6 ) . if a point ( a , b ) is selected at random from the triangular region , what is the probability that a - b > 0 ?
Options: a ) 1 / 5 , b ) 1 / 3 , c ) 1 / 2 , d ) 2 / 3 , e ) 4 / 5
[A]: d

[Q]: Problem: the height of a triangle is decreased by 5 % and its base increased by 10 % . its area will
Options: ['a ) decrease by 12.5 %', 'b ) increase by 12.5 %', 'c ) increase by 4.5 %', 'd ) increase by 25 %', 'e ) none of these']
[A]:
c