The problem asks us to estimate the angles in the given figures without measuring them directly. We should use referent angles to make our estimations. A right angle (90 degrees) is a useful reference.

1. Problem Description

The problem asks us to estimate the angles in the given figures without measuring them directly. We should use referent angles to make our estimations. A right angle (90 degrees) is a useful reference.

2. Solution Steps

Part 1:

A: This angle appears to be about 30 degrees.

B: This angle looks like a right angle. So, it's approximately 90 degrees.

C: This angle looks like slightly less than a right angle. So, it's approximately 80 degrees.

D: This angle is very small, much less than half of the angle at A. So, it's approximately 10 degrees.

Part 2:

A: This angle is obtuse, meaning it is greater than 90 degrees. It looks about $180 - 30 = 150$ degrees. So it's approximately 150 degrees.

B: This is a reflex angle, meaning it's more than 180 degrees and less than 360 degrees. The acute angle at B is about 70 degrees. The reflex angle would be $360 - 70 = 290$ degrees. So it's approximately 290 degrees.

C: This is an obtuse angle, and looks like it could be around 170 degrees.

D: This is a reflex angle. If we estimate the smaller angle to be approximately 50 degrees, then the larger angle would be approximately $360 - 50 = 310$ degrees.

3. Final Answer

Part 1:

A: Approximately 30 degrees

B: Approximately 90 degrees

C: Approximately 80 degrees

D: Approximately 10 degrees

Part 2:

A: Approximately 150 degrees

B: Approximately 290 degrees

C: Approximately 170 degrees

D: Approximately 310 degrees