Question

For AABC, find the measure of ZACD.
A
66°
45°
°
B
C
D​

Answer 1

Answer:

angle ACD=111°

Step-by-step explanation:

angle BAC+angle ABC+angle ACB=180°(Angle sum property)

66°+45°+angle ACB=180°

111°+angle ACB=180°

angle ACB=180°-111°

angle ACB=69°

angle ACB+angle ACD=180°

69°+angle ACD=180°

angle ACD=180°-69°

angle ACD=111°

Answer 2

Answer:

We know by angle sum property, A +B +C = 180°

66°+45°+C= 180°

111° + C = 180°

Therefore,angle C = 180°-111° = 69°

Now, as we know from the figure,that angle ACD is an exterior angle.

Clearly we can see that angle ACB and angle ACD form linear pair.

So,therefore, angle ACD + angle ACB = 180° -(linear pair)

ACD + 69° = 180°

ACD = 180° - 69°

ACD = 111°