Need help with this mathswatch question-did half don't know where i am going wrong

a) is correct

b) CD = 15,1 cm

Step-by-step explanation:

The cosine law can be used here:

b² = d² + c² - 2dc*cosβ

b² = 18² + 12,1² - 2 * 18 * 12,1 * cos 56°

b = √226,82

b = 15,1 cm

answer

a,b, and d

explanation

a reflection angle is more than

but less than;

an angle that measures

is a reflex angle.(true)

an angle that measures less than

is acute.(true)

provided we are considering angles greater or equal to zero.

an acute angle lies in the range.

an obtuse angle is less than 180° but more than 90°

an angle that measures 300° is obtuse (false)

an angle that measures 65° is an acute angle.(true)

is this part of a question or something