Some one help ASAP I will give you lots of points and brainliest, but please show work, or explain please.

Question 16 - RS, because chords are lines in the circle that is connected in two points of the circle.
Question 17 - RT, because a diameter is a chord that has the center point of the circle.
Question 18 - RT, it is not a radius
Question 19 - 19, diameter is double of a radius. 9.5 x 2 = 19
Question 20 - minor arc; 50°. Minor arc because it only has two labels (letters). If three label like arc ABC, then it is considered major. To get 50°, first calculate the angle Q. 180 - 100 = 80°. Next, add 80 and 50 together because they are part of the semicircle which was formed by DB. 80 + 50 = 130°. Use the total degrees of a semicircle (180) and subtract it by 130°.
180 - 130 = 50°
Question 21 - minor arc; 80°. Again, a semicircle, which is formed by AC, has a total angle of 180. So subtract 180 by 100 to get 80°.