A scale factor can be used to enlarge or reduce a shape. A missing length on a reduction/enlargement figure can be calculated by finding its linear scale factor.
Part ofApplications of MathsGeometry
Shape \(WXYZ\) is an enlargement of shape \(wxyz\). What is the length of \(XY\)?
XY is on the bigger figure, therefore we will be using an enlargement scale factor.
\(SF_{Enlargement} = \frac{Big}{Small} = \frac{9}{8}\)
Therefore \(XY\) is \(\frac{9}{8}\)times \(xy\).
So, \(XY = \frac{9}{8} \times 4 = 4.5cm\)
Shape \(WXYZ\) is an enlargement of shape \(wxyz\). What is the size of angle \(WXY\)?
In an enlargement or reduction of a shape the angles stay the same. So angle \(WXY\) is \(57^{\circ}\).
The sides of a rectangle measure \(8cm\) and \(6cm\).
If the rectangle is to be enlarged using scale factor \(\frac{3}{2}\) what will be the new lengths of the sides?
\(\frac{3}{2}\times 8 = 12cm\)
\(\frac{3}{2}\times 6 = 9cm\)
The new lengths will be \(12cm\) and \(9cm.\)
The sides of a rectangle measure \(20\,cm\) and \(28\,cm\).
If the rectangle is to be reduced using scale factor \(\frac{3}{4}\) what will be the new lengths of the sides?
\(\frac{3}{4}\times 20 = 15cm\)
\(\frac{3}{4}\times 28 = 21cm\)
The new lengths will be \(15cm\) and \(21cm\).