First, we are given that the inscribed angle of arc CB which is angle D is equal to 65°. This is half of the measure of the arc which is equal to the measure of the central angle, ∠O.
m∠O = 2 (65°) = 130°
Also, the measure of the angles where the tangent lines and the radii meet are equal to 90°. The sum of the measures of the angle of a quadrilateral ACOB is equal to 360°.
m∠O + m∠C + m∠B + m∠A = 360°
Substituting the known values,
130° + 90° + 90° + m∠A = 360°
The value of m∠A is equal to 50°.
<em>Answer: 50°</em>
Use the formula m = y2 - y1
————
x2 - x1
(-1 is x1, 5 is y1) (3 is x2, 13 is y2)
13 - 5 8
——— = — = 2
3 - (-1) 4
2 is the slope
If right is supposed to be eight then answer is 81
For problems like this you can move the y's on the bottem up top by fliping the sign of the exponent (in this case 7 to -7) and MULTIPLYING it with EVERYTHING on top, then because of properties of multplication you can add the exponents to combine them into one term (in this case add 3 and -7 to get -4)

If any of this does not make sense let me know and ill try to clarify better