Question

A sheet of paper
the area
pet of paper measures 30 cm by 20 cm. A strip 4 cm wide is cut from it all around. Find
ea of the remaining sheet and also the area of the strip cut-out.​

Answer 1

Area left = 264 cm²

Area cut  out = 336 cm²

Step-by-step explanation:

plz refer diagram attached simultaneously

LET THE PAPER initially be in the shape of   ABCD  

with AB = 30    , BC = 20

now the 4 cm wide strip is taken away (shown by green colour )

the green colour part is taken away and we are left with EFGH

total initial area ABCD = 30*20

                                        = 600 cm²

the length of EF and FG  can be found as 4 cm is taken away from both side the length decreases by 8 cm

EF = AB-8                     FG = BC-8

    = 30-8                            = 20-8  

    = 22  cm                            = 12 cm

Area of left EFGH  = 22*12

                              =     264 cm²

AREA total = area left + area cut out

area cut out  = AREA total  - area left

                          = 600 - 264

                           = 336 cm²