Part 1. Definition
In this task, you need to answer the given multiple-choice question on geometry. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.
Part 2. 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
Answer: d
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"
Part 3. Exercise
Problem: a horse is tethered to one corner of a rectangular grassy field 36 m by 20 m with a rope 12 m long . over how much area of the field can it graze ? 
Options: a ) 154 cm 2 , b ) 113 m 2 , c ) 123 m 2 , d ) 115 m 2 , e ) none of these
Answer:
b