The circumference of a circle is always calculated by 2

R
So if R=2.5 m this circumference is 2*

*2.5 m
Which is 5

m (choice B)
Hope this helped!
Angle b = 87 (vertically opposite angles)
I Suppose anyone can be good at trigonometry, all it takes is a willing mind and a good teacher.
Imagine to have three segment: 1 is x, another is x+7 and the last is x-5. You know that their sum is 50, so you can write:
x+(x+7)+(x-5)=50
simplify:
3x+7-5=50
3x=48
x=16
16+7=23
16-5=11
So the thee sides are 11, 16 and 23.
Hope this helped.
2
Length x width= area
3/4 x blank= 3/2
So then you can divide area by the given length
3/2 divided by 3/4= 2
And to check your answer you would put 2 in as your width
3/4 x 2= 6/4. And 6/4 reduces to 3/2