Odpowiedź :
7.
a = 30 m
b = 2a = 2 * 30 = 60 m
P= ab
P = 30 * 60
P = 1800 m2
O = a + a + b + b
O = 30 + 30 + 60 + 60 = 180 m
odp: pole wynosi 1800 m2 i trzeba kupić 180 m siatki.
8.
a = 9 cm
b = ?
O = 30 cm
a + a + b + b = O
30 cm = 9 + 9 + 2b
30 cm = 18 + 2b | -18
12 = 2b |:2
b = 6 cm
P = ab
P = 9 * 6 = 54 cm2
9.
a = 7 cm
P = a * a
P = 7 * 7
P = 49 cm2
10.
a = 40 m
P = a * a
P = 40 * 40
P = 1600 m2
1 ar = 100 m2
x arów = 1600 m2
x arów = 1600/100
x arów = 16
odp: pole powierzchni ma 1600 m2 i jest to 16 arów.
a = 30 m
b = 2a = 2 * 30 = 60 m
P= ab
P = 30 * 60
P = 1800 m2
O = a + a + b + b
O = 30 + 30 + 60 + 60 = 180 m
odp: pole wynosi 1800 m2 i trzeba kupić 180 m siatki.
8.
a = 9 cm
b = ?
O = 30 cm
a + a + b + b = O
30 cm = 9 + 9 + 2b
30 cm = 18 + 2b | -18
12 = 2b |:2
b = 6 cm
P = ab
P = 9 * 6 = 54 cm2
9.
a = 7 cm
P = a * a
P = 7 * 7
P = 49 cm2
10.
a = 40 m
P = a * a
P = 40 * 40
P = 1600 m2
1 ar = 100 m2
x arów = 1600 m2
x arów = 1600/100
x arów = 16
odp: pole powierzchni ma 1600 m2 i jest to 16 arów.
bok 1 - 30m
bok 2 - 2×30m=60m
P= 30×60=1800m²
L=2×30+2×60=60+120=180m
Odp. Potrzeba 180m siatki.
Zadanie 8:
30=2×9+2×x
30=18+2x
12=2x/:2
6=x
P=6×9=54cm²
Zadanie 9:
P=7²=49cm²
Odp. Pole kwadratu wynosi 49cm².
Zadanie 10:
P=40²=1600m²= 16a