It is known that OA = 3cm, ∠ OAB = 30 ° the position relationship between a circle with o as the center and 3cm long as the radius and a straight line AB is______ ．

It is known that OA = 3cm, ∠ OAB = 30 ° the position relationship between a circle with o as the center and 3cm long as the radius and a straight line AB is______ ．

As shown in the figure: when passing through point O, make OD ⊥ AB at point D, ∵ OA = 3cm, ∵ OAB = 30 °, ∵ od = 12oa = 1.5cm, ∵ 3 ≈ 1.7 ＞ 1.5, ∵ line AB intersects with ⊙ o

It is known that ∠ AOB = 30 °, P is a point on the edge OA, and op = 5cm. If the circle with P as the center and R as the radius is tangent to ob, then the radius R is___ ．

Let PD ⊥ ob be d. ∵ in a right triangle pod, ∠ AOB = 30 °, P is a point on the edge OA, and op = 5 cm, ≁ PD = 2.5 (CM). To make a straight line tangent to a circle, r = 2.5 cm

Given that ∩ AOB = 60 degrees, P is the point on OA, and op = 4cm, then the position relationship between the circle with P as the center and the radius of double radical three and the straight line ob is

Make the vertical line of OB through point P, and the vertical foot is C
In RT △ OPC
∠AOB=60° OP=4
Then PC = 2 √ 3
Because PC = R PC ⊥ ob
Circle and ob circumscribed