right triangle tree fell over

Question

Have rt. triangle start with A in left corner.  <A =  30 degrees.  Base (AB) is 97 inches.  BC is altitude = x.  <B = 90 deg.  CA is hypo = y.

Need to get original height of tree ( in feet).  tk u.

Answer 1

Kathryn,

 

You have the 30-60-90 triangle (one of the 2 special ones that you supposedly need to know everything about).

 

If AC (or CA) is hypotenuse and ∠B is 90°, then line AB is adjacent if the right angle triangle.

=> cos(A) =  adj 

                   hypo

 

=> hypo =     adj       =   69 inches 

                   cos(A)         cos(30°)

 

 

hypo = 79.67

The height of the tree is the length of the hypotenuse of the triangle it makes after falling 30°. Or, at least that's how I understand it. ∴ height = 80 inches

I hope this helps