Question

3. Assume lines that look tangent are tangent. Find the length of the line

segment indicated by the ?

Answer 1

20

Explanation:

The point of contact of the tangent and the diameter of the circle is a right angle.

Thus the triangle with legs 12 and 2 × 8 = 16 is right

Using Pythagoras' identity.

The square on the hypotenuse is equal to the sum of the squares on the other 2 sides, that is

?² = 12² + 16² = 144 + 256 = 400 ( take the square root of both sides )

? =
`√(400)` = 20