Answer
$33cm$ wide and $7.5cm$ high
Work Step by Step
We can determine the required dimensions as follows:
First we find the width
$w=\frac{W_w x_e}{x_e+x_w}$
We plug in the known values to obtain:
$w=\frac{(1.3m)(0.50m)}{0.50m+1.50m}$
$\implies w=33m=33cm$
Now the height can be calculated as
$h=\frac{x_wx_e}{x_e+x_w}$
We plug in the known values to obtain:
$h=\frac{(0.30m)(0.50m)}{0.50m+1.50m}$
$\implies h=0.075m=7.5cm$
