请帮忙做一个讲解这道题的视频，要求简单明了。谢谢。---**Extraction Content:**
**Question Stem:**
6. 定义: 对角线互相垂直且相等的四边形叫做“神奇四边形”.
(1)我们学过下列四边形: ①平行四边形; ②矩形; ③菱形; ④正方形. 其中是“神奇四边形”的是_____. (填序号)
(2)如图 1,在正方形 ABCD 中, E 为 BC 上一点, 连接 AE, 过点 B 作 BG ⊥ AE 于点 H, 交 CD 于点 G, 连接 AG, EG.
①判定四边形 ABEG 是否为“神奇四边形”;
②如图 2,点 M,N,P,Q 分别是 AB, AG, GE, EB 的中点, 求证: 四边形 MNPQ 是“神奇四边形”.
(3)如图 3,点 F,R 分别在正方形 ABCD 的边 AB, CD 上, 把正方形沿直线 FR 翻折, 使得 BC 的对应边 B'C' 恰好经过点 A, 过点 A 作 AO ⊥ FR 于点 O. 若 AB'=2, 正方形的边长为 6, 求线段 OF 的长.
**Images:**
**Figure 1:**
* **Type:** Geometric figure (Square and lines)
* **Main Elements:**
* Square ABCD with vertices labeled counterclockwise from top-left.
* Point E on side BC.
* Line segment AE.
* Line segment BG starting from B, intersecting CD at G, intersecting AE at H.
* Line segment BG is perpendicular to AE, indicated by a right angle symbol at H.
* Line segments AG and EG.
* Labels: A, B, C, D, E, G, H.
**Figure 2:**
* **Type:** Geometric figure (Square and lines)
* **Main Elements:**
* Square ABCD with vertices labeled counterclockwise from top-left.
* Point E on side BC.
* Line segment AE.
* Line segment BG starting from B, intersecting CD at G, intersecting AE at H.
* Line segment BG is perpendicular to AE, indicated by a right angle symbol at H.
* Line segments AG and EG.
* Points M, N, P, Q labeled on segments AB, AG, GE, EB respectively.
* Line segments MN, NP, PQ, QM forming quadrilateral MNPQ.
* Labels: A, B, C, D, E, G, H, M, N, P, Q.
* Caption below figure: 图 2 (Figure 2).
* Caption below Figure 2: 第 6 题图 (Figure for Question 6).
**Figure 3:**
* **Type:** Geometric figure (Square with fold)
* **Main Elements:**
* Original square ABCD indicated by dashed lines.
* Points F on AB and R on CD.
* Line segment FR (the fold line).
* Folded portion of the square, showing the new position of BC as B'C'.
* The line segment B'C' passes through point A.
* Point B' is labeled. Point C' is labeled. Point A is labeled.
* Line segment AO is drawn from A, perpendicular to FR at O.
* Point O is labeled on FR.
* Labels: A, B, C, D, B', C', F, R, O.
* Dashed lines indicate the original position of BC and CD.
* Caption below figure: 图 3 (Figure 3).