a b c d

a

The given quadrilateral is a rhombus because all the sides are equal. Therefore, Area of rhombus = \(\frac{1}{2}\) × d1 × d2 (Here, d1 = diagonal 1, and d2 = diagonal 2) According to question d1 = 2.5 and d2 = 3 cm Hence, Area of quadrilateral = \(\frac{1}{2}\) × 2.5 × 3                               = \(\frac{1}{2}\) × 7.5 = 3.75 cm2 Hence, option a is correct.