Name the reference angle in radians for an angle of -315 degree

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angle measure.

In the rectangle below ac=30 units what is de

Refer to interactive solution 17.45 to review a method by which this problem can be solved. the fundamental frequencies of two air columns are the same. column a is open at both ends, while column b is open at only one end. the length of column a is 0.504 m. what is the length of column b?