The perimeter of this shape is 40cm
Calculate the value of x

x = 8

Step-by-step explanation:

The perimeter (P) is calculated as

P = 2(l + b) ← l is length and b is breadth

Here l = 12 and b = x , P = 40, then

2(12 + x) = 40 ( divide both sides by 2 )

12 + x = 20 ( subtract 12 from both sides )

x = 8

d) 30 units^2

area of rectangle = l × b

we know,

length = 10 unit

breadth = 3 unit

applying the formula,

= l × b

= 10 × 3

= 30 unit^2

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step-by-step explanation: