What is the area of a trapezoid abcd with bases ab and cd if: m∠c=m∠d=60°, ab = bc = 8 cm

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Draw point E on CD so that AE ⊥ CD. Then the distance DE is 8cos(60°) = 4, and the height AE is 8sin(60°) = 4√3. The length of CD is 8+2×4 = 16. The area of the trapezoid is the product of the height and the average base length:

... A = (b1 +b2)/2×h = (8 cm + 16 cm)/2×(4√3 cm) = 48√3 cm² ≈ 83.14 cm²