waecmaths question:
In the diagram $\left| XY \right|=12cm,\left| XZ \right|=9cm,\left| ZN \right|=3cm$ and $\left| ZY \right|=$ calculate $\left| MY \right|$
Option A:
3cm
Option B:
4cm
Option C:
5cm
Option D:
6cm
waecmaths solution:
$\begin{align} & \text{Using similar triangles} \\ & \frac{\left| XZ \right|}{\left| XY \right|}=\frac{\left| XZ+ZN \right|}{\left| XY+MY \right|} \\ & \frac{9}{12}=\frac{9+3}{12+\left| MY \right|} \\ & 12+\left| MY \right|=\frac{12\times 12}{9} \\ & 12+\left| MY \right|=16 \\ & \left| MY \right|=4 \\\end{align}$
maths year:
maths topics: