A parallelogram containing a `60^0` angle has perimeter `p` and its longer diagonal is of length `ddot` Find its area.

Explanation

To find the area of a parallelogram with a \(60^\circ\) angle, given its perimeter \(P\) and the length of its longer diagonal \(D\), we can follow these steps:

### Step 1: Define the sides of the parallelogram
Let the lengths of the sides of the parallelogram be \(X\) and \(Y\). Since the perimeter \(P\) is given, we can express it as:
\[ P = 2(X + Y) \]
From this, we can derive:
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