Mariela is standing in a building and looking out a window at a tree. the tree is 20 feet away from mariela, mariela's line of sight creates a 42 degree angle of elevation, and her line of sight creates a 31 degree of depression. what is the height, in feet, of the tree?

30.01 feet.

Step-by-step explanation:

You need to remember this identity:

Observe the figure attached, where is the height in feet of the tree.

You need to calculate of the Triangle 1, where:

Substitute values into and solve for :

Now you need to calculate of the Triangle 2, where:

Substitute values into and solve for :

Then the height in feet of the tree is:

he used the algebra tiles correctly.

step-by-step explanation:

given : 3x(2x-1)

solution :

since he used algebra tiles .

armando's solution is the same in the solution shown in figure

as he distributed 2x into x and x and wrote them vertically

and also write   -1 vertically

and 3x into x and x and x and wrote it horizontally

performing the multiplication in the algebra tiles we get

and solving the given expression :

3x(2x-1)

since solving the expression using tiles   and solving the expression algebraically we get the same answer

thus   we can choose the first statement as the answer to this problem which is "he used the algebra tiles correctly".

don't know sorry bru

step-by-step explanation: