Question

Find the surface area 4cm 5cm 6cm 13cm

Answer 1

$A_\Delta=\dfrac{1}{2}\cdot6\cdot4=12\ cm^2\\\\A_{[]_1}=6\cdot13=78\ cm^2\\\\A_{[]_2}=5\cdot13=65\ cm^2\\\\A=2A_\Delta+A_{[]_1}+2A_{[]_2}\\\\A=2\cdot12+78+2\cdot65=24+78+130=232\ cm^2$