Can someone me with this geometry problem, ?

Hello from MrBillDoesMath!

72

Discussion:

Total Surface area = area of pyramid base + 4 ( area of triangular face)

In our case this becomes

                                 4*4                               + 4(  (1/2) (4)(7) )  =

                                 = 16 + (2)(4)(7)

                                 = 16 + 56        

                                 = 72

which is the first choice.  

Note: the area of a triangular face was computed using (1/2) b h, which in our case is

(1/2) (4) (7)

Thank you,

MrB

180-142=38 for the acute angle next to the entry

90+38=128

180-128=52

a=52

step-by-step explanation: