Tangent Method

• 1). Calculate the height of your transit or other angle measuring device from the forest floor to the top of the device. Note the measurement in pencil on a piece of paper.
  
  
• 2). Pin your cloth measuring tape to the redwood at the height calculated in step 1.
  
  
• 3). Extend your tape outward from the tree until you are able to see the redwood's uppermost point.
  
  Fasten your tape to the forest floor using a rock or other heavy object.
  
  
• 4). Set up your transit at the end point of the tree and determine the angle to the tree's top.
  
  
• 5). Calculate the tangent of the vertical angle multiplied by the length of the tape from the base of the tree to the transit location.
  
  Add the height of the tree above the transit to the height of the transit above ground level. This calculation will give you the height of the tree from base to tip.