The measure of angle a is 137.
Remember that the opposite angles equal to 180. So a+c=180 and b+d=180.
So we subtract 43 from 180 to find the missing angle a.
180-43=137.
a=137
Un tercio ,,,,.........,,.
Multiply length times width times height and once u get the total multiply that by two :
ex :
length:10
width:10
height:10 10x10x10=1000x2=2000