20. If cos(68°) = a, which of the following is true? a. sin(68°) = a
b. sin(220) = a
C. sin(689) = 90 - a
d. sin(220) = 90 - a

lockers 1, 4, 9, 16, 25, 40, and 49 are open

i ran through it by the other answer is wrong

180°

step-by-step explanation:

sum of equilateral triangle=180°

< n=60°

< m=120°°[angle supplementary of equilateral angle]

< m+< r+< x=360°(sum of exterior angle of triangle)