If angle DCA measures 50 degrees, what does angle ACB measure?

A.140
B.90
C.40

#2.If angle ACD measures 60 degrees, what does angle ACB measure?

A.15
B.30
C.150

Part 1:

Angle DCB is a right angle.

So, angle DCA + angle ACB = 90

Angle ACB = 90 - angle DCA = 90-50=40

Answer is option C. 40

Part 2:

Angle DCB is a right angle.

So, angle DCA + angle ACB = 90

Angle ACB = 90 - angle DCA = 90-60=30

Answer is option B. 30