The base of a rectangular trapezoid is 12.7, and one of the corners is 60 degrees. Find the large side of the trapezoid.

Let the bases be equal to a = 12, b = 7, <q = 60 °. If you draw the height to the larger side “a” from the second vertex, then a right-angled triangle with sides (a – b), lateral side – c, and an angle <60 ° will be separated. Whence (a – b) = cos 60 ° * c, whence c = (a – b) / cos 60 ° = (12 – 7) / cos 60 ° = 5 / (1/2) = 2 * 5 = 10.