5a - 4a = -9 - 8a
a = -9 - 8a
9a = -9
a = -1
Negative 1 over 11
negative 1 over 30
1 over 30
1 over 11
-1/6*-1/5 = 1/30
As you can see there are two triangles but it can be done calculating just for one. First we must understand how formula for area of triangle works.

Where
represents base (hypotenuse) and
as height of the triangle.
We know that:

Using this data we fill the formula.

Hope this helps.
r3t40
Answer:
See below
Step-by-step explanation:
IN a right triangle , remember S-O-H-C-A-H-T-O-A <===memorize this!
sin z = O/H = opposite side/hypotenuse = 16/20
cos z = A/H = adjacent / hy[potenuse = 12/20
tan z = O/A = 16/12