Which biconditional statement is true? A shape is a rectangle if and only if the shape has exactly four sides and four right angles. A shape is a trapezoid if and only if the shape has a pair of parallel sides. A shape is a triangle if and only if the shape has three sides and three acute angles. A shape is a square if and only if the shape has exactly four congruent sides.

Answer:The first one: A shape is a rectangle if and only if the shape has exactly four sides and four right angles.Step-by-step explanation:The true statement is the first one:A shape is a rectangle if and only if the shape has exactly four sides and four right angles.