It is given that two sides of a triangular field are 85m and 154m
Consider the third side as x m
It is given that the perimeter = 324m
We can write it as
85 + 154 + x = 324
On further calculation we get
x = 324 – 85 – 154
By subtraction
x = 85 m
Consider a = 85 m, b = 154 m and c = 85 m

By multiplication
Area = 2772 m2
We know that
Area of the triangle = ½ × b × h
By substituting the values
½ × 154 × h = 2772
On further calculation
77 × h = 2772
So we get
h = 2772/77
By division
h = 36 m
Therefore, area of the field is 2772 m2 and the length of the perpendicular from the opposite vertex on the side measuring 154m is 36m.