The base of the ABCD quadrangular pyramid PABCD is a rectangle with sides 4 and 6, and its side edges are 5. Find the surface area of the pyramid.

The heights of the side faces of the pyramid with side 4 are √21, and with side 6 are 4. Therefore, the surface area of the pyramid is 24 + 4√21 + 24, i.e. 48 + 4√21.

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