SEAMO 2019 — Paper D — Grade 7–8 Question 19

Question 19

In sector OAB, the source writes $\widehat{AB}=18$ cm. OA and OB are tangent to two mutually tangent circles. The circle centered at C has radius six cm. Find the radius of the circle centered at D.

Question illustration

$2$
$3$
$4$
$5$
None of the above