Question

a quadrilateral with four congruent sides and an angle measuring $60^{circ}$ must be a
rectangle
rhombus
trapezoid
square

Explanation:

1. Recall the definitions:

• A rectangle has four right angles (90°) and opposite sides congruent. Since there's a 60° angle, it can't be a rectangle.
• A rhombus has four congruent sides, and its angles can be any (not necessarily 90°). A quadrilateral with four congruent sides and a 60° angle fits the rhombus definition.
• A trapezoid has at least one pair of parallel sides, but the given info (four congruent sides) doesn't match trapezoid's main property (it's more about rhombus here).
• A square has four congruent sides and four right angles (90°), but we have a 60° angle, so it's not a square.

Answer:

B. rhombus