The vertices of the quadrilateral ABCD divide the length of the circumscribed circle in the ratio AB: BC:
| October 9, 2021 | education
The vertices of the quadrilateral ABCD divide the length of the circumscribed circle in the ratio AB: BC: CD: CA = 2: 17: 4: 13. Find the area of the quadrilateral if AC = 8 cm, BD = 9 cm.
Let’s define the degree measures of arcs AB, BC, СD, АD.
2 * X + 17 * X + 4 * X + 13 * X = 360.
36 * X = 360.
X = 100.
Arc BC = 17 * 10 = 170. Then the inscribed angle BAC = 170/2 = 85.
Arc AD = 13 * 10 = 130. Then the inscribed angle ABD = 130/2 = 65.
In triangle AOB, angle AOB = 180 – 85 – 65 = 30.
Let’s define the area of the quadrilateral through the diagonals and the angle of their intersection.
Savsd = (1/2) * АС * ВD * Sin30 = 8 * 9 * 1/4 = 18 cm2.
Answer: The area of the quadrangle is 18 cm2.
One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.
