1.(a) AB
(b) CB, AC or AB
(c) CB
(d) EF
(e) OA, OC or OB

2. (a) and (b) 

(c) A, B, C and D
(d) Any circle, centre O

3. (a) RQS (b) RQ (c) SP and PQ, RQ and RS

(d) RSQ

4. (a) a = 90°, b = 67.4°, c = 22.6°

5. (a) a = 53°, b = 53°

(b) c = 48°, d = 48°, e = 120°, f = 30°

(c) g = 31°, h = 90°, i = 59°, j = 59°, k = 90°

(d) m = 98°, n = 155°, p = 73°

6. (a) q = 53°, r = 53°, s = 37°, t = 53°, u = 53°, v = 37°

(b) OXW (c)OXY and XYZ