Question

Oblicz pole koła o obwodzie:

0,12 π mm

⅔ π km

4dm

Oblicz obwód koła o polu

m²

0,25 π mm²

2 π dm²

Answer 1

Zadanie 1

0,12 π mm:

2πr = 0,12π mm /:π
2r = 0,12 /:2
r = 0,06
P = πr²
P = π(0,06)²
P = 0,0036π mm²
================================

⅔ π km:

2πr =  ⅔π km /:π
2r = 2/3 /:2
r = 1/3
P = πr²
P = 1/9π km²
================================
4dm:
2πr = 4dm /:2
πr = 2 /:π
r = 2/π
P = πr²
P = π(2/π)²
P = 4/π dm²

===================================
Zadanie 2

4/9πm²:

πr² = ⁴/₉π m² /:π
r² = 4/9
r = 2/3
Obw = 2πr
Obw = 2 * π * 2/3
Obw = 4/3π m
==============================

πr² = 0,25π mm² /:π
r² = 0,25
r = 0,5
Obw = 2πr
Obw = 2 * π * 0,5
Obw = π mm
=============================
πr² = 2π dm² /:π
r² = 2
r = √2

Obw = 2πr
Obw = 2 * π * √2
Obw = 2√2π dm

Answer 2

 

1a)

 

1b)

 

1c)

 

2a)

 

2b)

 

2c)