Question

ex.14 este urgent dau coroana

Answer 1

A=Lxl
P=2x(L+l)
A)P=32 cm
L=7xl
32=2x(7l+l)
32=2x8l
16l=32
l=32/16
l=2 cm
L=7x2
L=14 cm
A=14x2
A=28 cm patrati


B) P=72cm
l=L:11=>L=11xl
72=2x(11 l+l)
72=2x12l
24l=72
l=72/24
l=3 cm
L=11x3
L=33 cm
A=33x3
A=99 cm patrati


C) P=120 cm
l=3/7 xL

120=2x(L+3/7L)
120=2x(7L+3L)/7
120=2X10L/7
20L/7=120
L=120:20/7
L=120X7/20
L=6x7
L=42 cm
l=3/7x42
l=3x6
l=18 cm

A=42x18
A=756 cm patrati