Answer: 15
Step-by-step explanation:
Opposite angles of a cyclic quadrilateral are supplementary, so:

The translated answer would be 124.1
Answer:
The area of the regular hexagon is 
Step-by-step explanation:
we know that
The area of a regular hexagon can be divided into 6 equilateral triangles
so
step 1
Find the area of one equilateral triangle

we have

----> is the apothem
substitute


step 2
Find the area of 6 equilateral triangles

1st problem:
Use the Pythagorean theorem:
a^2+b^2=c^2
49+361=c^2
c^2=410
c=20.24
The answer is 20m
2nd problem:
First calculate the height using the Pythagorean theorem:
a^2+b^2=c^2
20^2+b^2=625 (i got 20 {radius} by half-ing the base edge length)
400+b^2=625
b^2=225
b=15
Next, solve for the volume:
V=a^2*h/3
V=40^2*15/3
V=1600*5
V=8000
The answer is the second choice or B.