Answer:
∠AOB = 120°
∠BOC = 140°
∠BOD = 140°
Step-by-step explanation:
First, find X !
Full circle is 360°
360 = (2x + 80) + (5x + 40) + 4x + x
360 = 12x + 120
240 = 12x
x = 20°
Substitute the X
∠AOB ≡ (2x + 80) =
(2(20) + 80) = 120°
∠BOC ≡ (5x + 40) =
(5(20) + 40) = 140°
∠BOD = ∠AOB + ∠DOA ≡
120 + x = 120 + 20 = 140°
By either long or synthetic division, it's easy to show that

The quartic will be exactly divisible by

when the numerator of the remainder term vanishes, or for those values of

such that

I'm not sure how to count the number of solutions (software tells me it should be 80), but hopefully this is a helpful push in the right direction.
Answer:the answer is 4 to the square root of 2
Step-by-step explanation:
Apothem is the height of a triangel formed by two consecutive vertices with the center. the are of this triangle = 1/2 s 8 = 4s
there area 12 such triangles in the regular 12 side polygon
So area = 12 * 4 s = 48 s
Answer:
n=35
Step-by-step explanation:
Subtract 25 from both sides to isolate the variable
n+25=60
-25 -25
n=35
Hope this helps! :)