question_answer

A field is in the form of an isosceles trapezium whose perimeter is 215 m. One of its non-parallel side is 50 m. What is the sum of its parallel sides?

A)  115m

B)  60m

C)  165m

D)  135m

Correct Answer: A

Solution :

Let ABCD be the field which is in the form of an isosceles trapezium. AD = 50 m [Given]     \[\therefore BC\text{ }=\text{ }50\text{ }m\] [Non-parallel sides of an isosceles trapezium are of equal length] Perimeter of trapezium ABCD                         \[=AB+BC+CD+DA\] \[\Rightarrow 215=(AB+CD)+50+50\] \[\Rightarrow 215=100+(AB+CD)\] \[\Rightarrow (AB+CD)=215-100=115m\] \[\therefore \] Sum of parallel sides \[=\text{ }115\text{ }m\]