Answer:
Prob.3
Denote r: radius of circle O
Formula for calculating AOB sector:
Area = pi*r^2*angle/360
Area = pi*r^2*45/360 = 18 pi
=> r^2 = 18*360/45 = 144
=> r = 12
For prob.4, give it a try, follow the formula I gave. Good luck !
(answer : r = 6)
Answer:
12750
Step-by-step explanation:
The sequence of visitors is
50, 100, 200, 400, .....
This is a geometric sequence
with common ratio r = 2
The sum to n terms is found using
= 
( a is the first term )
= 
= 50 × 255 = 12750
Triangle DEF hope that helps
Step-by-step explanation:
because we can also find out the value of x in second equation like this
3x=21
x=21/3
x=7
Answer:
Can you give us a picture?
