Given:
m∠CDR = 85°
To find:
The length of arc RC and arc CBR.
Solution:
The measure of the central angle is congruent to the measure of the intercepted arc.
⇒ m∠CDR = m(ar RC)
⇒ m(ar RC) = 85°
Complete angle of circle = 360°
⇒ m(ar RC) + m(ar CBR) = 360°
⇒ 85° + m(ar CBR) = 360°
Subtract 85° from both sides.
⇒ 85° + m(ar CBR) - 85° = 360° - 85°
⇒ m(ar CBR) = 275°
The measure of arc RC is 85°.
The measure of arc CBR is 275°.
