The two diagonals are not necessarily equal in a

Options

A. rectangle
B. square
C. rhombus
D. isosceles trapezium

Answer

To solve the question "The two diagonals are not necessarily equal in a:", we will analyze the options provided and determine which shape does not have both diagonals equal.

### Step-by-Step Solution:

1. **Understand the Properties of Each Shape**:
- **Rectangle**: In a rectangle, the diagonals are equal in length.
- **Square**: A square is a special type of rectangle where all sides are equal, and the diagonals are also equal.
- **Rhombus**: A rhombus has all sides equal, but the diagonals are not necessarily equal. They bisect each other at right angles.
- **Isosceles Trapezium**: In an isosceles trapezium, the diagonals are equal in length.

2. **Identify the Shape with Unequal Diagonals**:
- From the properties listed, we see that both the rectangle and square have equal diagonals. The isosceles trapezium also has equal diagonals. However, the rhombus has diagonals that are not equal.

3. **Conclusion**:
- Therefore, the shape in which the two diagonals are not necessarily equal is the **Rhombus**.

### Final Answer:
The correct answer is **Option 3: Rhombus**.

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