Answer:

Explanation:
In this problem we have
 -----> given problem
 -----> given problem
 ---> is a common side both triangles
 ---> is a common side both triangles
In the right triangle RSX
Applying the Pythagoras Theorem
 ------> equation A
 ------> equation A
In the right triangle XST
Applying the Pythagoras Theorem
 ------> equation B
 ------> equation B
remember that -----> 

Substitute
 ------> equation C
 ------> equation C
Compare equation A and equation C
