Answer:
John ski down the mountain is 1285.37 feet.
Step-by-step explanation:
Given : John is skiing on a mountain with an altitude of 1200 feet. The angle of depression is 21.
To find : About how far does John ski down the mountain ?
Solution :
We draw a rough image of the question for easier understanding.
Refer the attached figure below.
According to question,
Let AB be the height of mountain i.e. AB=1200 feet
The angle of depression is 21 i.e. 
We have to find how far does John ski down the mountain i.e. AC = ?
Using trigonometric,




Therefore, John ski down the mountain is 1285.37 feet.
Answer:
CD ≠ EF
Step-by-step explanation:
Using the distance formula
d = 
with (x₁, y₁ ) = C(- 2, 5) and (x₂, y₂ ) = D(- 1, 1)
CD = 
= 
=
= 
Repeat using (x₁, y₁ ) = E(- 4, - 3) and (x₂, y₂ ) = F(- 1, - 1)
EF = 
= 
=
= 
Since
≈
, then CD and EF are not congruent