How can I tell if it is a redwood, sequoia, or cedar as they all have red trunks, when I look at a tree?

Question

How can I tell if it is a redwood, sequoia, or cedar as they all have red trunks, when I look at a tree?

Answer 1

Look at the texture of the bark and the shape of the leaves.

Answer 2

Go into the woods where all three kinds of trees exist, with a friend who knows trees and they can point out and explain to you how the leaves are different. Looking on-line will only give you a vague idea until you actually experience the difference first hand.