Answer:
16 * √3 cm² or approximately 27.71 cm²
Explanation:
Given the 8 cm length of the diagonal and the 30° (π/6 radians) angle with one of the sides, we can calculate the width and height of the rectangle using:
8 * cos(π/6) = 8 * ((√3)/2) = 4 * √3
8 * sin(π/6) = 8 * (1/2) = 4
Multiply those two values together to get the area and you get
16 * √3 cm²