Let a and b represent the heights of the corresponding buildings (in meters).
... a = b +271 . . . . . . . a is 271 meters taller than b
... 2b -a = 211 . . . . . . if a is subtracted from twice b, the result is 211
Use the expression for a in the first equation to substitute for a in the second.
... 2b - (b+271) = 211
... b = 482 . . . . . . . . . . . simplify and add 271
... a = b +271 = 753
Building a is 753 meters tall; building b is 482 meters tall.
Its 37.5 just device them and round to the nearest tenth.
There is some disagreement whether parallelograms, which have two pairs of parallel sides, should be regarded as trapezoids. Some define a trapezoid as a quadrilateral having only one pair of parallel sides (the exclusive definition), thereby excluding parallelograms.
In other words, sometimes.
