Answer:
The measure of the arc RQ is 160°
Step-by-step explanation:
- <em>In any circle, the measure of the subtended arc of an inscribed angle is twice the measure of this inscribed angle</em>
- <em>The measure of any circle is 360°</em>
Let us use these rules to solve the question
In the given figure
∵ ∠RPQ is an inscribed angle subtended by arc RQ
∴ m of arc RQ = 2 × m∠RPQ
∴ m∠RPQ = 5x + 15
∴ m of arc RQ = 2 × (5x + 15)
→ Multiply the bracket by 2
∴ m of arc RQ = 2(5x) + 2(15)
∴ m of arc RQ = 10x + 30
∵ The measure of the circle = 360°
∵ The sum of the measures of arcs RQ, QP, and PR equals the measure
of the circle
∵ m of arc QP = 6x - 12
∵ m of arc PR = 9x + 17
→ Add them and equate the sum by 360°
∴ 10x + 30 + 6x - 12 + 9x + 17 = 360
→ Add the like terms in the left side
∵ (10x + 6x + 9x) + (30 - 12 + 17) = 360
∴ 25x + 35 = 360
→ Subtract 35 from both sides
∴ 25x = 325
→ Divide both sides by 25 to find x
∴ x = 13
→ To find the measure of arc RQ substitute x by 13 in its measure
∵ m of arc RQ = 10(13) + 30 = 130 + 30
∴ m of arc RQ = 160°
∴ The measure of the arc RQ is 160°
