Answer:
77.2°
Step-by-step explanation:
Consider the triangle JKR.
∠KJR=108.6 (lies on the same line as ∠RJA, angles on a straight line add up to 180)
All the angles in a triangle add up to 180, so:
∠JKR+∠KJR+∠JRK=180
∠JKR+108.6+32.8=180
∠JKR=38.6=∠RKA
Consider ∠RKA. This angle stands on the same arc as ∠RCA.
Since the angle at centre is twice the angle at circumference, 2(∠RKA) = ∠RCA.
2(∠RKA) = ∠RCA
2(38.6)=∠RCA
∠RCA=77.2°
