Find the surface area of the regular pyramid

Greetings from Brazil!
[tex]4\dfrac{1}{2} =\dfrac{9}{2}[/tex]
[tex]Af1=\dfrac{b\cdot h}{2} \cdot 4\\\\\\Af1=\dfrac{\dfrac{9}{2} \cdot 4}{2} \cdot 4\\\\\\Af1=\dfrac{\dfrac{36}{2} }{2} \cdot 4\\\\\\Af1=\dfrac{18}{2} \cdot 4\\\\Af1=9\cdot 4\\\\Af1=36~m^2[/tex]
[tex]Af2=l^2\\\\Af2=(\dfrac{9}{2})^2\\\\\ Af2=\dfrac{81}{4}\\\\Af2=20,25~m^2[/tex]
[tex]At=Af1+Af2\\At=36+20,25\\At=56,25~m^2[/tex]
I hope I helped you! =)