The angle of the parallelogram is 150 (degrees), and the sides are 11 cm and 3√3 cm.
The angle of the parallelogram is 150 (degrees), and the sides are 11 cm and 3√3 cm. Find the S of the parallelogram and its smaller diagonal.
The area of a parallelogram is equal to the product of the sides of the parallelogram multiplied by the sine of the angle between them.
S = AB * AD * SinABC = 3 * √3 * 11 * Sin150 = 33 * √3 * 1/2 = 16.5 cm2.
The sum of the adjacent angles of the parallelogram is 180, then the angle BAD = 180 – 150 = 30.
From the triangle ABD, by the cosine theorem, we determine the length of the diagonal BD.
BD ^ 2 = AB ^ 2 + AD ^ 2 – 2 * AB * AD * CosBAD = (3 * √3) 2 + 112 – 2 * 3 * √3 * 11 * Cos30 = 27 + 121 – 66 * √3 * √3 / 2 = 148 – 99 = 49.
ВD = √49 = 7 cm.
Answer: The area of the parallelogram is 16.5 cm2, the smaller diagonal is 7 cm.