Question

Aditi wants to put decorative tape around the borders of a rectangular cardboard which is 50 cm long and 45 cm wide. Which of these expressions represents the length of tape, in cm, required to cover its borders?and what is its length? 

50 × 45) ; 2250 cm.
(50 + 45) ;195 sq.cm.
2(50 × 45) ; 9500 cm.
2(50 + 45) ; 190 cm.

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Answer 1

option (4) 2(50 + 45) ; 190 cm

Step-by-step explanation:

Given:

• Length of the cardboard = 50 cm
• Breadth of the cardboard = 45 cm

To find:

Expression for the length of the tape as well as its measure.

Solution:

Dimensions of the rectangular cardboard : 50 cm×45 cm

Now, as we know;

$\bf Perimeter\:of\:a \:rectangle=\boxed{2(l+b)}$

Putting values in the above formula,

Perimeter of the cardboard;

= 2(50 + 45)

= 2×95

= 190 cm

Hence, the expression 2(50 +45) represents the length of decorative tape of the measure 190 cm.

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Know More:-

• Area of a rectangle = l×b
• Perimeter of a square = 4×side
• Area of a square = (side)²

Answer 2

2(50 + 45) ; 190 cm

Given:

Length of the cardboard = 50 cm

Breadth of the cardboard = 45 cm

To find:

The length of the tape as well as measure.

Solution:

Dimensions of the rectangular cardboard : 50 cm × 45 cm

As we know .

Perimeter of rectangle - 2 ( l + b )

In the above formula,

Perimeter of the cardboard :-

$= 2(50 + 45)$

$= 2 × 95$

$= 190 \: cm$

Hence, the expression 2(50 +45) represents the length of decorative tape of the measure 190 cm.

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The correct Option is ( A ) .