Odpowiedzi

2010-04-08T17:04:41+02:00
P=18 cm2
h=3cm
a= x+5= 8
b=x= 3

p= 1/2 * (a+b) *h
18= 1/2 * (x+x+5) * 3 / * 2
36= 2x+5*6
36-30=2x
6=2x
x=3

podstawy to 3 cm oraz 8cm
2010-04-08T17:06:18+02:00
A - podstawa
b - podstawa, b = a + 5
h - wysokość = 3 cm

P = ½(a+b)h
18 = ½(a + a + 5)3
18 = ½(2a + 5)3
18 = (a + 2,5)3
18 = 3a + 7,5
18 - 7,5 = 3a
10,5 = 3a/:3
a = 3,5

b = a + 5
b = 3,5 + 5
b = 8,5
2010-04-08T17:13:05+02:00
P=½(a+b)h
18=½(a+a-5)*3
18=½*(2a-5)*3/*2
36=(2a-5)*3
36=6a-15/+15
6a=51/:6
a=8,5cm
b=a-5
b=8,5-5
b=3,5