Calculate the area of the parallelogram if its altitudes are 3 and $2\sqrt{3}$ cm, and the angle $\mathrm{between\; tham\; is}$ 60°!

The paralell sides of the trapezoid orund the circle has length of 8 cm and 2 cm. Calculate the area of the trapezoid!

Length of the sides of cyclic trapezoid are: AB = 5 cm, BC = 2,5 cm, CD = 2 cm and DA = 2,5 cm.

a) Calculate the angles of the trapezoid!
b) Determine the ratio of ABC and ACD triangles!
c) The inner angles of the trapezoid are marked with an arc of 5 mm radius. Calculate the sum of the four arc lengths!