P, Q, R and S are respectively the mid-points of sides AB, BC, CD and DA of quadrilateral ABCD in which AC=BD and `ACbotBD`. Prove that PQRS is a square.

Explanation

To prove that the quadrilateral PQRS is a square, we will follow these steps:

### Step 1: Identify the midpoints
Let P, Q, R, and S be the midpoints of sides AB, BC, CD, and DA of quadrilateral ABCD, respectively.

### Step 2: Use the given conditions
We are given that AC = BD and AC is perpendicular to BD. This means that the diagonals AC and BD intersect at a right angle.

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