Simplify them until they can be simplified no more, then compare both sides.
The cofunction of cos is sin(90-x)
90 degrees is equal to PI/2
The cofunction becomes sin(PI/2 - 2PI/9)
Rewrite both fractions to have a common denominator:
PI/2 = 9PI/18
2PI/9 = 4PI/18
Now you have sin(9PI/18 - 4PI/18)
Simplify:
Sin(5PI/18)
-1/3 It cant be the others because -1 is already at the edge and is not the number, 1/3 is positive but -1/3 is left of zero, therefore negative and 1 is right of zero, so is positive.
-1/3 is the correct answer.
Answer:
isoceles
Step-by-step explanation:
because isosceles triangle have 2 sides with equal measurement and a same angle can be formed 1 or 3 times not 2 times.