# Question

Pls help with the perimeter question. Thanks a lot!

As all three rectangles are identical, i.e. the same, and Length BC = AD, that implies that the length of each rectangle is twice the length of its breadth. Counting each breadth as one unit, AB = DC = 3 units, AD = BC = 2 units.

So that means 3 + 3 + 2 + 2 units = 180 cm;

10 units = 180 cm

1 unit = 18 cm.

BC is 2 units (or 2 x AD), therefore = 36 cm

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As for the second question.

The answer should be 11 x 13 = 143 chairs

As Jaydon is sitting in one of the chair, on his left and right side got 5 chairs on each side,
there will be 10 + 1 (the one he’s sitting) = 11 chairs  in each row.

And, infront and back got 6 chairs each,
there will be 12 + 1 (the one he’s sitting) = 13 rows.

Therefore, there will be 143 chairs altogether in the hall.

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Basically perimeter equal to length(L) + breath(B) times 2.

By reversing it, 180 / 2 = 90                                                                                                                                      This is the length plus the breath.

From AB and BC we see 2L + B = 90                                                                                                             From AD and DC we see L + 3B = 90                                                                                                                     From this we know that length is twice of breath (L = 2B)

For ABCD, there is 3L +4B = 180                                                                                                                             Now it can be change to 3L + 2L =180                                                                                                                                                                            L = 180/5                                                                                                                                                                        L = 36cm

Working:

180/2 = 90

2L + B = 90

L + 3B = 90

L = 2B

3L + 4B = 180

5L = 180

L = 180/5

= 36cm

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