What are the characteristics of a fire classification pictogram? Colored background.
They are circular.
Letter, indicating the fire classification.
White symbol / lettering
check

i think it because equal matrices have equal dimensions, only square matrices can be symmetric. for all indices and . every square diagonal matrix is symmetric, since all off-diagonal elements are zero. in linear algebra, a real symmetric matrix represents a self-adjoint operator over a real inner product space.

an obstruction

d) physical means can be used to separate the components of air.