Check the picture below.
keeping in mind that the point of tangency for a radius line and a tangent is alway a right-angle, since the "red" chord is parallel to the "green" tangent line outside, then the chord is cutting the "green" radius there in two equal halves at a right-angle, as you see in the picture.
we know the chord is 10 units long, so 5 + 5, since is perpendicularity with the radius will also cut the chord in two equal halves.
anyhow, all that said, we end up with triangle you see on the right-hand-side, and then we can just use the pythagorean theorem.

Answer:
The measure of angle RST is 
Step-by-step explanation:
see the attached figure to better understand the problem
we know that
-----> equation A
-----> equation B
equate equation A and equation B




The measure of angle RST is equal to

6x+28=25
or,x=-1/2
Step-by-step explanation:
corresponding sides i think so
Step-by-step explanation:
-3(-x -3y) = 3( x +3y) = 3x+9y
Erm I would say it comes from the same money pot (account) but not 100% sure what your tryin to ask