Relax

Respuesta :

The measure of an angle formed by a tangent and a secant intersecting outside the circle is equal to one-half the difference of its intercepted arcs. 

T = 1/2 (RU - SU)
21 = 1/2(119 - SU)
42 = 119 - SU
77 = SU

The answer is B. 77

Hope this helps =)

qrse

Answer:

77 degrees (option B)

Step-by-step explanation: