Respuesta :

Answer:

radius = 9.5 cm

Step-by-step explanation:

If 2 chords intersect then the product of the parts of 1 chord is equal to the product of the parts of the other chord, that is

PT × TQ = ST × TR

PT × 3 = 4 × 12 = 48

3 PT = 48 ( divide both sides by 3 )

PT = 16

then

diameter = PT + TQ = 16 + 3 = 19 cm

radius = 19 ÷ 2 = 9.5 cm