Attempt following question by selecting a choice to answer.
c
What is the measure of the marked exterior angle of the triangle?
[Given x = 57 and y = 34.]DDD cccA.
c146
B.
c151
C.
c149
D.
c143
cc
A
Step 1: In ΔABC, m∠ABC = 57 and m∠BCA = 34
Step 2: Since side BC is extended to the point D, exterior angle of ∠ACB is ∠ACD.
Step 3: In the figure, Interior angle at C + Exterior angle at C = 180°
Step 4: m∠BCA + m∠ACD = 180.[Substitute the angles.]
Step 5: [Substitute the value of ∠BCA.]
34 + m∠ACD = 180.
Step 6: [Simplify.]m∠ACD = 146.
Step 7: Measure of the shown exterior angle of the triangle is 146.