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Right-angled Triangles, SM-Bank 050

Use Pythagoras' Theorem to calculate the perimeter of the rectangle below, correct to 1 decimal place.  (3 marks)

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\(13.0\ \text{m}\ (1\ \text{d.p.})\)

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\(\text{Find side length of rectangle.}\)

\(\text{Pythagoras’ Theorem states:  }a^2+b^2=c^2\)

\(\text{Let }b=3\ \text{and }c=4.6\)

\(\text{Then}\ \ a^2+3^2\) \(=4.6^2\)
\(a^2\) \(=4.6^2-3^2\)
\(a\) \(=\sqrt{12.16}\)
\(a\) \(=3.487\dots\)

 
\(\text{Perimeter}\)

\(=2\times 3.487\dots+ 2\times 3\)

\(=12.974\dots\approx 13.0\ \text{m}\ (1\ \text{d.p.})\)