Answer:

1. 20 cm

2. 8 cm

3. 90 degrees

4. 45 degrees

Step-by-step explanation:

1. Line AB is congruent to line AC.

2. Line BD is half of line BC.

3. Angle ADB is a right angle.

4. Angle B is congruent to angle C.

Answer:

1. 20cm

2. 8cm

3. 90 degrees

4. 45 degrees