Kennedy buys cell phone cases for $4.50 and sells them to her friends for $18.00. What is the percent mark-up? (HINT: use the percent of change method)

Answer is in the file below

cutt.ly/nz6VGda

∠acb = 8°

step-by-step explanation:

∠xba lies on the circle and is half the measure of the intercepted arc ax

hence

measure of arc ax = 2 × 42° = 84°

∠acb is outside the circle and is

∠acb = (arcab - arcax ), hence

∠acb = 0.5 (100 - 84) = 0.5 × 16° = 8°