Jawaban:

a . L kotak = s²

= 21 • 21

= 441 Cm²

L set lingkaran = 1 • 1 • π • d²

_ _

2 4

= 1 • 1 • 22 • 28 • 28

_ _ __

2 4 7

= 308 Cm²

luas d arsir = L kotak - L set lingkaran

= 441 - 308

= 133 Cm²

K O = π • d K = 21 + 21 + 21 - 33

= 22 •21 = 63 - 33

__ = 30 Cm²

7

= 66 : 2

= 33 Cm²

b . L kotak = s²

= 42 • 42

= 1.764 cm²

L lingkaran = 1 • π • d²

__

4

= 1 • 22 • 42 • 42

_ __

4 7

= 1.386 cm² • 2

= 2.772 Cm²

L arsir = 1.764 + 2.772

= 4.536 Cm²

K arsir = s + s + s + s + ( k O 1 • 4 )

__

2

= 168 + ( K = 1 • π • d )

__

2

= 168 + ( K = 1 • 22 • 42 )

__ __

2 7

= 168 + 66

= 234 cm²

c. L set lingkaran besar

= 1 • 1 • π • d²

__ __

2 4

= 1 • 1 • 22 • 56 • 56

__ __ __

2 4 7

= 1.232 Cm²

L lingkaran kecil = 1 • π • d²

__

4

= 1 • 22 • 21 • 21

__ ___

4 7

= 346 ,5 cm²

L arsir = 1.232 - 346,5

= 885,5 Cm²

K O besar = 1 • π • d

__

2

= 1 • 22 • 56

__ __

2 7

= 88 Cm²

K O kecil = π • d

= 22 • 21

__

7

= 66 Cm²

K arsir = 88 - 66

= 22 Cm²

Penjelasan dengan langkah-langkah:

maaf kalau salah sama keknya poinnya kedikitan :)