Which two types of quadrilaterals always have diagonals that are equal in length?

The two types of quadrilaterals that always have diagonals that are equal in length are the rectangle and the square.

Step 1: Understand the properties of quadrilaterals Quadrilaterals are four-sided polygons. They have various types, including squares, rectangles, parallelograms, rhombuses, trapezoids, and kites, each with its own unique properties.

Step 2: Identify the quadrilaterals with equal diagonals A rectangle is a quadrilateral with four right angles. In a rectangle, the diagonals are equal in length. A square is a special type of rectangle where all four sides are of equal length. Therefore, in a square too, the diagonals are equal in length.

So, the two types of quadrilaterals that always have diagonals of equal length are rectangles and squares.