In the given diagram, $O$ is the center of the circle. We are given that $\angle SQR = 60^{\circ}$, $\angle SPR = y$, and $\angle SOR = 3x$. We need to find the value of $x + y$.
2025/4/29
1. Problem Description
In the given diagram, is the center of the circle. We are given that , , and . We need to find the value of .
2. Solution Steps
Since is the center of the circle, is the central angle subtended by the arc . is an inscribed angle subtended by the same arc .
We know that the inscribed angle is half of the central angle. Therefore, we have:
Also, we know that the angle at the center is twice the angle at the circumference subtended by the same arc. Therefore:
Since (radii of the same circle), is an isosceles triangle. Thus .
Also, we have .
Since , we have .
Since , we have .
.
We are given that . Also, and subtend the same arc SR. Thus . Since , .
Now consider the quadrilateral .
The angles and are subtended by the same chord .
Also
We are given . Also , which implies triangle is an isosceles triangle. Therefore . Similarly , which means . We are given .
Consider the angle . The inscribed angle that subtends the same arc is . , so .
In quadrilateral , and . The sum of the angles of quadrilateral is
3
6
0. We can consider the $\angle SOR$. $\angle SOR = 2 \angle SQR$.
.
Since the total angles in the quadrilateral add up to ,
.
Consider triangle . and . Therefore .
.
We are given .
We also have inscribed angle corresponds to at center.
Since the arc SR subtends angle at , we have .
Then , . Since , we have . Therefore .
Therefore .
3. Final Answer
100°