Sebidang tanah berbentuk trapesium sama kaki dengan keliling 48 m dan sisi sisi yang sejajar panjangnya 8m dan 20 m. Jika harga tanah rp 75.000, 00 tiap m2, mak

kll = s1 + s2 + s3 + s4
48 = 8 + 20 + s + s
48 - 8 - 20 = 2s
20 = 2s
s = 10

mencari tinggi
a² + b² = c²
6² + b² = 10²
b² = 100 - 36
b = 8

luas = 1/2 x t x (a+b)
= 1/2 x 8 x 28
= 112 m²

Harga tanah
112 x 75.000
= Rp8.400.000

TRAPESIUM SAMA KAKI
K = 48 m
a = 20 m
b = 8 cm
harga tanah per m^2= Rp 75.000,00
sisi miring = sm
K = a + b + 2 × sm
48 = 20 + 8 + 2sm
48 = 28 + 2sm
2sm = 48 - 28
2sm = 20
sm = 20/2
sm = 10
t trapesium = akar [sm^2 - (1/2×(a-b))^2]
= akar [10^2 - (1/2×(20-8))^2]
= akar [10^2 - (1/2×12)^2]
= akar [10^2 - 6^2]
= akar [100 - 36]
= akar 64
= 8 m
L trapesium = 1/2 × (a + b) × t trapesium
= 1/2 × (20 + 8) × 8
= 1/2 × 28 × 8
= 112 m^2
harga tanah seluruhnya
= L trapesium × harga tanah per m^2
= 112 × 75.000
= 8.400.000
Jadi harga seluruh tanah itu adalah
Rp 8.400.000,00