The figure shaded was created by placing the vertices of a square within the circle. What is the area of the shaded region? Use 3.14 to approximate, remember to answer using cm2

Which sum or difference identity would you use to verify that cos (180° - q) = -cos q? a.) sin (a -b) = sin a cos b – cos a sin b b.) cos (a -b) = cos a cos b – sin a sin b c.) cos (a -b) = cos a cosb + sin a sin b d.) sin (a + b) = sin a cos b + cos a sin b