Let's first find out their factors.
90's factors are :

190's factors are :

The common factors of 90 and 190 are :
1,2,5 and 10.
The greatest one among these is, 10. So the greatest factor of 90 and 190 is 10.
#5 is 1845 and #6 should b 4
Answer:
Option B. 
Step-by-step explanation:
we know that
The area of a circle is equal to

we have

substitute

Remember that
radians subtends the complete circle of area 
so
by proportion
Find the area of the related sector for a central angle of
radians
Let
x------> the area of the related sector

Answer:
Step-by-step explanation:
Plug in: 