In an equilateral trapezoid, a large base is 12 cm, and the lateral side is 4 cm. The acute angle is 60 degrees.

In an equilateral trapezoid, a large base is 12 cm, and the lateral side is 4 cm. The acute angle is 60 degrees. Find a smaller base.

The smaller base of the isosceles trapezoid is part of the larger one. If we divide the lower base by perpendiculars into three segments, then the larger of them will be equal to the upper base, and the other two are equal to each other. One of these segments is equal to half of the lateral side, since it lies opposite an angle of 30 °. Let’s find a smaller base.

12 – 4/2 * 2 = 8 centimeters.

Answer: 8 centimeters.