A net of arectangular pyramidis shown. Therectangular base haslength 24 cm andwidth 21 cm. Thenet of the pyramidhas length 69.2 cmand width 64.6 cm.Find the surfacearea of the pyramid.

A net of arectangular pyramidis shown Therectangular base haslength 24 cm andwidth 21 cm Thenet of the pyramidhas length 692 cmand width 646 cmFind the surfacea class=

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Solution

The Image will be of help

To find x

[tex]\begin{gathered} x+24+x=69.2 \\ 2x+24=69.2 \\ 2x=69.2-24 \\ 2x=45.2 \\ x=\frac{45.2}{2} \\ x=22.6 \end{gathered}[/tex]

To find y

[tex]\begin{gathered} y+21+y=64.6 \\ 2y+21=64.6 \\ 2y=64.6-21 \\ 2y=43.6 \\ y=\frac{43.6}{2} \\ y=21.8 \end{gathered}[/tex]

The diagram below will help us to find the Surface Area of the Pyramid

The surface area is

[tex]SurfaceArea=A_1+2A_2+2A_3[/tex]

To find A1

[tex]A_1=24\times21=504[/tex]

To find A2

[tex]\begin{gathered} A_2=\frac{1}{2}b\times h \\ 2A_2=b\times h \\ 2A_2=21\times22.6 \\ 2A_2=474.6 \end{gathered}[/tex]

To find A3

[tex]\begin{gathered} A_3=\frac{1}{2}bh \\ 2A_3=b\times h \\ 2A_3=24\times21.8 \\ 2A_3=523.2 \end{gathered}[/tex]

The surface Area

[tex]\begin{gathered} SurfaceArea=A_1+2A_2+2A_3 \\ SurfaceArea=504+474.6+523.2 \\ SurfaceArea=1501.8cm^2 \end{gathered}[/tex]

Thus,

[tex]SurfaceArea=1501.8cm^2[/tex]

Ver imagen LouiseV488457
Ver imagen LouiseV488457