An isosceles trapezoid is described around the circle, the angle at the base of which is 30 degrees.

An isosceles trapezoid is described around the circle, the angle at the base of which is 30 degrees. The height of the trapezoid is 4 cm. Find the sum of the lengths of the bases of the trapezoid.

In a right-angled triangle СНD, the CH leg is located opposite an angle of 300, then its length is equal to half the length of the hypotenuse of the СD.
CH = СD / 2. СD = 2 * CH = 2 * 4 = 8 cm.
Since the trapezoid is isosceles, then AB = СD = 8 cm, and the sum of the sides will be equal to: AB + СD = 8 + 8 = 16 cm.
A circle can be inscribed into a trapezoid only when the sum of its opposite sides is equal to each other. Then BC + AD = AB + СD = 16 cm.
Answer: The sum of the lengths of the bases of the trapezoid is 16 cm.



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