What is the total weight of the steel gate

Simple. since we know the weight per given length, we simply need to know the total length of all steel used. the perimeter is easy as it is given, 2×12 and 2×5 for a total perimeter of 24+10 or 34m. now the diagonals must be calculated...

since this is a right triangle, one could easily use a trig function to calculate, but to keep it simple pathag. theorum a2+b2=c2, where the 2 means squared. rearrange to c=sqrt(a2+b2), or 12 squared + 5 squared...giving 144+25=169. then take square rt of 169. this is length of one diagonal, remember to multiply by 2 since there are two diagonal pieces. add this to total perimeter of 34m above.

now that total length is known, simply multiply by weight/m for total weight

**remember units, as problems become complex keeping up with units can help u know if you are using right solving methods, like in heat transfer, energy equations, etc.

-362

step-by-step explanation:

(12)(4)+2(12)-34(12)+2(12)-3

  \/         \/         \/         \/

  48 +   24 -   408 + 24 - 3

      \   /               \   /

          72     -     432 - 3 = -363