The two diagonals are not necessarily equal in aSelect an answerArectangleBsquareCrhombusDisosceles trapezium

Break Down the Problem

1. Identify the properties of each shape mentioned (rectangle, square, rhombus, isosceles trapezium).
2. Determine which shape has diagonals that are not necessarily equal.

Relevant Concepts

1. Rectangle: Opposite sides are equal, and diagonals are equal.
2. Square: All sides are equal, and diagonals are equal.
3. Rhombus: All sides are equal, and diagonals are not necessarily equal (they bisect each other).
4. Isosceles Trapezium (Isosceles Trapezoid): Has one pair of parallel sides, and diagonals are equal.

Analysis and Detail

1. In a rectangle and square, the diagonals are equal.
2. In a rhombus, the diagonals are not equal but bisect each other perpendicularly.
3. In an isosceles trapezium, the diagonals are equal.

Since we are looking for a shape where the diagonals are not necessarily equal, the appropriate choice is the rhombus.

Verify and Summarize

Upon analyzing each shape's properties and their diagonal characteristics, the rhombus stands out as the only figure that does not have equal diagonals by definition.

Final Answer

The correct answer is C) rhombus.