Find x if abcd is a square and angle c = 1/2 x – 5.

any angle in a square = 90 degrees

so C=1/2x-5 has to equal 90

90=1/2x-5

95 = 1/2x

190=x

check (1/2)190-5 = 90

 x = 190

∠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°