Answer:
Step-by-step explanation:
Given that angle A is in IV quadrant
So A/2 would be in II quadrant.
sin A = -1/3
cos A = 
(cos A is positive since in IV quadrant)
Using this we can find cos A/2

Answer:
Oh cool! The answer is 90 since a and c or parallel, b cuts through them perpendicularly, forming a right angle.
Step-by-step explanation:
A=wl, so the answer is A :)
B looks the most reasonable
It is not an equilateral triangle. To prove this, you must solve for x. I found x by setting 2x+5.2 = 3x+1.2 to get x=4. Then I plugged 4 into equation to see if they were equal. 2(4)+5.2= 13.2 and 3(4)+1.3=13.2 but 2(4)+6.2=14.2. This allows us to conclude that the triangle is not equilateral because all of the sides are NOT congruent. Hope that helped:))