It MUST be a right triangle for this formula to work, please comment if it is not a RIGHT triangle

a and b being the lengths of the legs of the triangle (the 2 sides that are not the hypotenuse) and c being the hypotenuse's length.
Well, don't you already have the t value ,-7.
Answer:
(C-D)/A = B
Step-by-step explanation:
C = AB + D
Subtract D from each side
C-D = AB
Divide each side by A
(C-D)/A = AB/A
(C-D)/A = B