Answer:

82 m.

• AB = CD = 5 cm and BC = AD = 3 cm

• So, the perimeter of the rectangle ABCD = AB + BC + CD + AD = 5 cm + 3 cm + 5 cm + 3 cm = 16 cm

It can be written as 5 cm + 5 cm + 3 cm + 3 cm

= (2 × 5) cm + (2 × 3) cm

= 2 (5 + 3) cm

= 2 × 8 cm

= 16 cm

We add length and breadth twice to find the perimeter of a rectangle.

Step-by-step explanation:

Solution:

Length of the display board = 8 m

Breadth of the display board = 6 m

Perimeter of the display board = 2(Length + Breadth)

= 2(8 + 6) m

= 2 × 14 m

= 28 m.

Cost of ribbon is $15 per metre.

Therefore, total cost for 28 m long ribbon = $15 × 28

= $420.

hope it helps.

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