Answer:

Step-by-step explanation:
According to the trigonometric ratios in aright triangle :

Given: ΔBCA ~ ΔSTR
Since , corresponding angles of two similar triangles are equal.
So, ∠C = ∠T ...(i) [Middle letter]
In triangle STR
...(ii)
From (i) and (ii), we have

Answer:
9.
Step-by-step explanation:
The highest power is 3*3 = 9, so it's 9.