If the figure ABCD is a parallelogram then \sin( (a + b)/(4) ) ​

Question

If the figure ABCD is a parallelogram then

`\sin( (a + b)/(4) )`
​

Answer 1

(A + B)/4 = [(A + C) + (B + D)]/4 = (180 + 180)/4 = 360/4 = 90 degrees

So, sin((A + B)/4) is equal to sin(90 degrees), which is equal to 1.