luas bangunan di samping setengah lingkaran 70cm =

Nomor 6

D = 70 cm
r = 1/2 d = 35 cm

Maka
L = ½ πr²
L = ½ (22/7)(35)²
L = 1925 cm²

Jawaban A.

no.6

luas lingkaran=
[tex]\pi \:{r}^{2} [/tex]

d=70:2=35->r
r=35
bag: 1/2

luas lingkaran=
[tex] \frac{1}{2} x \frac{22}{7} x{35}^{2} [/tex]
[tex] \frac{1}{2} x \frac{22}{7} x1.225[/tex]
[tex] \frac{1}{2} x22x175[/tex]
[tex] \frac{1}{2} x3.850[/tex]
[tex] = 1.925[/tex] cm (A)

jawabannya A

no.7

luas P. panjang=P×L
=14×28
=392

luas lingkaran= 1/4×pi×r2
=1/4×22/7×14×14
=1/4×22×28
=1/4×616
=616:4
=154 cm
jadi luas P.panjang + luas lingkaran= 392+154
=546 (C)
jawabannya C

no.8

k-trapesium
=32+40+32
=104

k-lingkaran
=1/2×22/7×28
=1/2×22×4
=1/2×88
=44

jadi, k-trapesium + k-lingkaran= 104 + 44= 148 (B)

jawabannya B

semoga membantu^^