Question

Tugas matematika kelas IX...
mohon bantuannya.. Tqu Before;;)
4 nomor tentang luas permukaan...

Answer 1

1. a. LP=4πr²=4×3,14×2×2=50,24m²=5024cm²
   b. LP=1/4×4πr²=1/4×4×22/7×21×21=1386cm²

2. 154=4×22/7×r²
   154×7/88=r²
   12,25=r²
   r=3,5cm

3. LP=1/2×4×3,14×10×10
       =628cm²

4. LP=1/4×4×22/7×35×35
       =3850cm²=38,5m²
harga bahan = 38,5×35000=1.347.500
harga tukang = 38,5×50000=1.925.000
total biaya = 1.347.500 + 1.925.000
               = 3.272.500

dicek lagi ya :)

Answer 2

1.
a)4.π.r.r
4.3,14.2.2
12,56.4
=50,24cm^2
b)D=21cm|| r=10,5 cm
4.π.r.r
4.3,14.10,5.10,5
12,56.110,25
=1384,7 cm^2
2.) 154 cm^2= 4.π.r.r
= 4.(22/7).r.r
= 88/7.r.r
=12,5
r^2=154/12,5
=√12,32
=3,5 cm
3.)3.π.r.r
3.3,14.10.10
3.314
=942 cm^2
4.) D=35m || r =17,5 m
= 2.π.r.r
2.3,14.17,5.17,5
6,28.306,2
= 1923,2 m^2
= 1923,2.(35+50rb)
=1923,2.85000
=Rp.163,472,000
coba entar di cek yaa