1. ab is tangent to circle o at b. the diagram is not drawn to scale. . circle o. if ab = 9 and ao = 21.6, what is the length of the radius (r)? round the answer to the nearest tenth. a. 19.6. b.15.3*. c.23.4. d.12.6. 2. jk, kl, and lj are all tangent to circle o. the diagram is not drawn to scale. . triangle jlk with an inside circle o. if ja = 12, al = 15, and ck = 5, what is the perimeter of δjkl? (1 point). 34. 64 *. 32. 54. 3. wz and xr are diameters of circle c. the diagram is not drawn to scale. . . what is the measure of a. 355º. b.5º. c. 292º. d.243º.

1) The correct answer is A) 19.6

See the first picture attached.

A line tangent with a circle (AB) forms a 90° angle with the radius drawn from the tangent point (BO). This means that you can apply the Pythagorean theorem:
BO = √(AO² - AB²)
      = √(21.6² - 9²)
      = √(466.56 - 81)
      = √385.56
      = 19.6

2) The correct answer is B) 64

See the second picture attached.

When you have an incircle (a circle inscribed in a triangle), the distances between a vertex and the two nearest tangent points are equal to each other.

This means that:
JA = JB
LA = LC
KC = KB

Therefore the perimeter of ΔJKL will be: 
2 × (12 + 15 + 5) = 64

3) The question asks for the measure of arc ZWX
The correct answer is D) 243°

See the third picture attached.

We know that a diameter forms an arc of 180°, because it divides the circle into two equal parts.

Therefore, arc ZRW measures 180°.

In order to find arc ZWX you need to add arc ZRW and arc WX:
ZWX = ZRW + WX
         = 180 + 63
         = 243°