Respuesta :
Answer:
77°
Step-by-step explanation:
By the property of intersecting tangent and secant outside of a circle:
[tex]21 \degree = \frac{1}{2} ( 119 \degree - \widehat{SU} ) \\ \\ 42 \degree = 119 \degree - \widehat{SU} \\ \\ \widehat{SU} =119 \degree - 42 \degree \\ \\ \widehat{SU} =77\degree \\ \\ [/tex]
The mArc SU is option (B) 77 degrees
What is Tangent?
A straight line or plane that touches a curve or curved surface at a point, but if extended does not cross it at that point.
What is secant ?
A secant is a line that intersects a circle in exactly two points.
Here,
By the property of intersecting tangent and secant outside of a circle:
[tex]T=\frac{1}{2}(RU-SU)[/tex]
Here
T= 21 degrees
RU is the mArc RU = 119 degrees
Then,
[tex]21 =\frac{1}{2}(119-SU)\\ 42=119-SU\\SU=119-42[/tex]
SU = 77 degrees
Hence, the mArc SU is option (B) 77 degrees
Learn more about Tangent and secant here
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