Question

two circle of radius 17cm and 10cm intersect each other and the length of the common chord is 16 cm find the distance between their centre

Answer 1

Answer:

using pythagoras theorem,

x²+y² = 10² =100

and

(21-y)²+x² = 17²

⇒21²+y²-42y + x² = 17²

⇒ 441 - 42y + (y²+x²) = 289

⇒ 441 - 42y + 100 = 289

⇒ -42y = 289-100-441 = -252

⇒ y = 252/42 = 6

x = √100-y² = √100-36 = √64 = 8cm

chord length = 2x = 16cm

Answer 2

distance between the centers is 21 cm