tolong no.4 dan5 pakek jalan #tolongyah pakek jalan

4. luas pada denah:
[tex] = 12 \times 20 \\ = 240 \: {cm}^{2} [/tex]
jika skalanya 2:150 maka luas sebenarnya adalah
[tex] = \frac{luas \: denah}{skala} \\ = \frac{240}{ \frac{2}{150} } \\ = 240 \times \frac{150}{2} \\ = 120 \times 150 \\ = 18000 {cm}^{2} \\ = 1.8 {m}^{2} [/tex]
5.
a.
[tex] = \frac{1}{2} \times 7 \times 5 \\ = \frac{35}{2} \\ = 17.5 {cm}^{2} [/tex]
luas sebenarnya :
[tex] = \frac{17.5}{ \frac{2}{7} } \\ = 17.5 \times \frac{7}{2} \\ = \frac{122.5}{2} \\ = 61.25 {cm}^{2} [/tex]
b.luas segitiga:
[tex] = \frac{1}{2 } \times 15 \times (27 - 17) \\ = \frac{1}{2} \times 15 \times 10 \\ = 15 \times 5 \\ = 75 {cm}^{2} [/tex]
luas persegi panjang:
[tex]17 \times 15 = 255 {cm}^{2} [/tex]
luas total:
[tex]75 + 255 = 330 {cm}^{2} [/tex]
luas sebenarnya :
[tex] = \frac{330}{ \frac{1}{500} } \\ = 330 \times 500 \\ = 165000 {cm}^{2} \\ = 16.5 {m}^{2} [/tex]