Answer:
210.
Step-by-step explanation:
10.5 x 20 = 210
i hope that helps!!!
Answer:
area = 160 cm²
Step-by-step explanation:
area = (8x 4 x 4) + (4 x 4 x 2) = 160 cm²
Answer:-14, -26
Step-by-step explanation:
13-4=9
4-9=-5
From here you can see that the pattern is -9
-5-9=-14
23. is -14
16-2=14
2-14=-12
From here you can see that the pattern is -14
-12-14=-26
24. is -14
Answer: z = -5/-3
Step-by-step explanation:
(3z−11)+(6−6z)
3z - 11 + 6 - 6z
- 6z + 3z - 11 + 6
- 3z - 5
z = -5/-3
Circumference of a circle - derivation
This page describes how to derive the formula for the circumference of a circle.
Recall that the definition of pi (π) is the circumference c of any circle divided by its diameter d. Put as an equation, pi is defined as
π
=
c
d
Rearranging this to solve for c we get
c
=
π
d
The diameter of a circle is twice its radius, so substituting 2r for d
c
=
2
π
r
If you know the area
Recall that the area of a circle is given by
area
=
π
r
2
Solving this for r
r
2
=
a
π
So
r
=
√
a
π
The circumference c of a circle is
c
=
2
π
r
