Question

100 points.

Thanks in advance

Answer 1

• mAD=78°=m<1

As

m<3 is opposite to m<1 both the angles are equal

Now

m<3=m<1

• 78°

Answer 2

• A. 78°

Explanation:

Since both AC and DB are diameters, angle 3 is central angle.

Angles 1 and 3 are vertical angles, hence are of equal value.

Since the central angle has same value as the intercepted arc, we have:

• m∠3 = m∠1 = mAD = 78°

Correct choice is A