Answer:
20mm
Step-by-step explanation:
base=20mm
base x 2 because there are two long lines
20 x 2 = 40
42-40=2
amount needed on either side to balance
height=1mm
20 x 1 = 20mm
area = 20mm
Answer:
Let the length of the rectangle be 'l'
We have,
Perimeter of rectangle, P = 42mm.
[tex]or, 2(l+b) = 42\\or, l +b = \frac{42}{2} = 21\\or, l + 20 = 21\\or, l = 1mm\\[/tex]
Area of rectangle = [tex]lb = 1(20) = 20mm^{2}[/tex]