详细解答上面问题的解题过程。---**Question Number and Points:**
27. (8分)
**Problem Description:**
已知射线OM平分∠AOB, 点C为OM上任意一点,过点C作直线l//OB交射线OA于点D.
**Part (1):**
(1) 如图1, 若∠OCD = 30°, 则∠AOB = ______ °.
**Figure 1 Description:**
* Type: Geometric diagram.
* Elements:
* Point O: Origin.
* Rays OA, OB, OM: Emanating from O. OM is between OA and OB.
* Line l: Passes through C, parallel to OB.
* Point C: On ray OM.
* Point D: Intersection of line l and ray OA.
* Labels: A, B, C, D, O, M, l.
* Angle indicated: ∠OCD.
* Text Label: 图1 (Figure 1).
**Part (2):**
(2) 点E是射线DC上一动点 (不与点C, D重合), OF平分∠DOE交CD于点F, 过点F作FG//OM交OA于点G.
**Figure 2 Description:**
* Type: Geometric diagram.
* Elements:
* Point O: Origin.
* Rays OA, OB, OM: Emanating from O. OM is between OA and OB.
* Line segment CD: Part of the line l from Figure 1. E is on the extension of CD or DC. (Based on the text, E is on ray DC).
* Points C, D, E: Collinear. E is on ray DC but not C or D.
* Ray OF: Emanating from O, bisects ∠DOE, intersects CD at F.
* Point F: On line segment CD.
* Line segment FG: Starts at F, parallel to OM, intersects OA at G.
* Point G: On ray OA.
* Labels: A, B, C, D, E, F, G, O, M, l.
* Text Label: 图2 (Figure 2).
**Part (2)①:**
① 如图2, 若∠OCD = 60°, 当OE⊥CD时, 求∠OFG的度数.
**Part (2)②:**
② 当点E在运动过程中, 设∠OFG = α, ∠OEC = β, 直接写出α和β之间的数量关系.