Which of the following are identities? Check all that apply. A. cos(x + y) + cos(x - y) = 2cos x cosy
B. sin(x + y) - sin(x-y) = 2cosx siny
C. cos(x + y) + cos(x - y) = cos x -
- sin? y
D. sin(x - 7T) = - sinx

go and ask your mom to you

80° is the measure of gh

step-by-step explanation:

circle f is congruent to circle j

we have two circle with center f and j.

both circles are congruent. the radius of the circle would be equal.

see the attachment for the circle.

we are given ∠efd ≅ ∠gjh

therefore, arc (ed) = arc (gh)     (∴ circle f is congruent to circle j)

but ∠dfe=80°=arc (ed)

therefore, arc (gh) = 80°

thus, 80° is the measure of gh