Triangle LMN has sides measuring 7 meters and 6 meters and a
     Triangle LMN has sides measuring 7 meters and 6 meters and a perimeter of 16 meters.  Heron\'s formula: Area = Squareroot s (s - a) (s - b) (s - c)  What is the area of triangle LMN? Round to the square meter.  3 square meters  9 square meters  28 square meters  34 square meters 
  
  Solution
Perimeter is 16
Third side = 16-7-6 = 3
So, the area of triangle is :
s = a+b+c /2 = 16/2 = 8
By applying the Hero\' formula we have:
Area = sqrt( 8*1*2*5) = sqrt(80) ~= sqrt(81) = 9
Option B is right

