The area of the trapezoid is equal to the product of half the sum of the bases in height. We know the reasons, we will find the height of the trapezoid.
Draw the height as shown in the figure. The resulting triangle is rectangular. By definition of the sine, we can write: sin30 ° = h / 3 => h = 3 * sin30 °, sin30 ° = 1/2 (tabular value).
h = 3 * 1/2 = 1.5.
Straps = (3 + 9) / 2 * 1.5 = 9
Answer: the area of the trapezoid is 9
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.