The figure below shows concentric circles, both centered at 0.0
• Chord XY is tangent to the smaller circle
• The radius of the larger circle is 15cm
• The radius of the smaller circle is 12cm.
What is the length of chord XY?
A. 27 cm
B. 24cm
C. 18cm
D. 10cm

  C.  18 cm

Step-by-step explanation:

The ratio of the sides of the triangle shown is 12 : 15 = 4 : 5. We know it is a right triangle, so we know the missing side length completes the ratio

  3 : 4 : 5 = 9 : 12 : 15

Half of XY is 9 cm, so the length of the entire chord is 18 cm.

The chord is tangent to the inner circle, so makes a 90° angle with the radius to that tangent point. This tells you that the triangle shown is a right triangle. It also tells you that the short radius bisects the chord. The Pythagorean theorem can be used to find the length of the side not shown (half the chord length).

The unknown side (a) can be found from  ...

  15² = 12² +a²

  225 -144 = a² . . . . . . subtract 12²

  81 = a² . . . . . . . . . . .  simplify

  9 = a . . . . . . . . . . . . . take the square root

The chord length is 2a, so is ...

  2(9 cm) = 18 cm . . . . length of chord XY

options a,b,c are the right answer.

step-by-step explanation:

a linear parent function is always represented as y = x

if we write this function in the form of y=mx+c

⇒

or  

now if we plot a graph we will find these characteristics:

1) y intercept of the graph is zero so its a straight line passing through origin.

2) as we can see in both the forms of function written, values of x and y may be either positive or negative for the positive slope means points on the graph are either in first quadrant or in third one.

3) it's slope is one.