Answer:
Formula for the Arc length is given by:

As per the statement:
radius of circle(r) = 6 units
Angle (
) =
radian
Use conversion:

= 
then;
substitute these given values we have;
Use value of 

or

Simplify:

Therefore, the arc length of the arc substended in a circle with radius 6 units an angle of 7 pi/8 is 16.485 units
Answer:
The age of the youngest friend is 9 years old.
Step-by-step explanation:
3a = 30 - 3
= 27 ÷ 3
= 9
= 9 + 10 + 11 = 30
= 9 is the smallest number. So, the youngest friend is 9 years old.
X
+
6
−
5
=
8
−
2
+
6
−
5
=
8
−
2
Solve
1
Subtract the numbers
x
+
6
−
5
=
8
−
2
+
6
−
5
=
8
−
2
x
+
1
=
8
−
2
+
1
=
8
−
2
2
Subtract the numbers
x
+
1
=
8
−
2
+
1
=
8
−
2
x
+
1
=
6
+
1
=
6
3
Subtract
1
1
from both sides
x
+
1
=
6
+
1
=
6
x
+
1
−
1
=
6
−
1
+
1
−
1
=
6
−
1
4
Simplify
Subtract the numbers
Subtract the numbers
x
=
5
=
5