Which of the following is larger in area?
$a.Area=\frac{1}{2}bh$
$ =\frac{1}{2}\times10\times8$
$=40c m^{2}$
$b.Right angled tiangle=13^{2}=5^{2}+12^{2}$
$ =\frac{1}{2}\times5\times12$
$ =30cm^{2}$
$c.Equilateral triangle=\frac{\sqrt{3}}{4}\times10\times10$
$ =25\sqrt{3}$
$ =25\times1.732$
$=43.3cm^{2}$
$d.Right angled triangle= \frac{1}{2}\times3\times4$
$ =6ccm^{2}$