Odpowiedzi

2010-04-15T19:10:20+02:00
H = 2 dm = 20 cm
a = 12 cm
b = 3a
b = 3 * 12
b = 36 cm
P = (a + b) * h / 2
P = (12 + 36) * 20 / 2
P = 48 *20 / 2
P = 960 / 2
P = 480 cm²
1 dm² = 100 cm²
480 cm² = 4,8 dm²

Odpowiedź:
D
2010-04-15T19:10:21+02:00
H = 2dm = 20cm
a = 12cm
b = 12cm * 3 = 36cm
P = 1/2h * (a+b)
P = 1/2 * 20cm * (12cm+ 36cm)
P = 10cm * 48 cm
P = 480 cm2
P = 4,8 dm2
2010-04-15T19:12:39+02:00
Dane:
podstawa₁ (a)= 12cm
podstawa₂ (b)= 12cm * 3= 36cm
wysokość (h)= 2dm= 20cm

Szukane:
Pole trapezu (P)= ?

Wzór:
P= ½(a+b)*h

Obliczanie:
P=½(12cm+36cm)*20cm= (48cm)*10cm=480cm²= 4,8dm²

Odp:D