The second midpoint is (-15,8)
Answer: Addition
Step-by-step explanation: You can represent that as 10^5*10^-5
If you add the exponent values, you get 10^0 which is equal to 1. If you multiply them, you get 10^-25 which is wrong.
Tangent always meets radius at 90° angle.
Angle ABC = 90° so Pythagoras' theorem applies.
r² + 4² = (r+2)²
r² + 16 = r² + 4r + 4
12 = 4r
r = 3