Respuesta :

Answer:

= 8.9 units

Step-by-step explanation:

When a chord intersects with a tangent outside a circle then we use the relationship;

X ² = AO × BO, Where A and are the points of intersection of the chord an the circle, while O is the point of intersection between the chord and the tangent.

Therefore;

x² = 4 × 20 or 8 × 10

x² = 80

x = √80

= 8.944

 ≈ 8.9