Perimeter - rectangle

Find the perimeter of the rectangle. A rectangle with a base of (3 5/6) m and a height of (2 3/7) m
Its perimeter is x= meters. (Use fractions in your answer. )

Correct answer:

x =  12 ¹¹⁄₂₁ = 263/21 m

Step-by-step explanation:

$$\begin{gathered} a=3\frac{5}{6}=3+\frac{5}{6}=\frac{3\cdot 6+5}{6}=\frac{18+5}{6}=\frac{23}{6}\doteq 3.8333\text{m} \\ b=2\frac{3}{7}=2+\frac{3}{7}=\frac{2\cdot 7+3}{7}=\frac{14+3}{7}=\frac{17}{7}\doteq 2.4286\text{m} \\ x=2\cdot (a+b)=2\cdot (\frac{23}{6}+\frac{17}{7})=\frac{263}{21}\text{m}=12\frac{11}{21}\text{m}=12.5238\text{m} \end{gathered}$$

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