Math Problem Statement

Given: The circle centered at point [A] has a radius of length [AB]. The circles centered at points [B] and [D] have radii of length [DE]. Ray A B and ray A C intersect at point A. A circle arc centered at point A interesects point B on ray A B and point D on ray A C. One circle arc centered at point B and one circle arc centered at point D intersect at point A and point E. A ray connects points A and E so that rays A B, A D, and A E all start at point A. [A] [B] [C] [D] [E] Complete the proof that [\angle DAE \cong \angle BAE]. Step Statement Reason 1 [AB=AD] All radii of the same circle have the same length. 2

Both circles have radii of the same length. 3 [AE=AE] They're lengths of the same segment. 4

Side-side-side congruence (1, 2, 3) 5 [\angle DAE \cong \angle BAE] Corresponding parts of congruent triangles are congruent (4).

Solution

Let's complete the proof by filling in the missing steps in the two-column format. The goal is to prove that DAEBAE\angle DAE \cong \angle BAE.

Proof:

StepStatementReason
1AB=ADAB = ADAll radii of the same circle have the same length.
2BE=DEBE = DEBoth circles centered at BB and DD have the same radius (length DEDE).
3AE=AEAE = AEReflexive property (a segment is equal to itself).
4ABEADE\triangle ABE \cong \triangle ADESide-Side-Side (SSS) congruence (steps 1, 2, and 3).
5DAEBAE\angle DAE \cong \angle BAECorresponding parts of congruent triangles are congruent (CPCTC) (step 4).

Explanation:

  • Step 1: We know that ABAB and ADAD are radii of the circle centered at AA, so they are equal in length.
  • Step 2: Circles centered at BB and DD have the same radius, which is DEDE, so the lengths BEBE and DEDE are equal.
  • Step 3: The segment AEAE is shared between the two triangles ABE\triangle ABE and ADE\triangle ADE, so it is trivially equal to itself.
  • Step 4: Using the SSS postulate, triangles ABE\triangle ABE and ADE\triangle ADE are congruent because all corresponding sides are equal.
  • Step 5: Since ABEADE\triangle ABE \cong \triangle ADE, the angles DAE\angle DAE and BAE\angle BAE are congruent by CPCTC (corresponding parts of congruent triangles).

This completes the proof that DAEBAE\angle DAE \cong \angle BAE.


Do you want further details on any of these steps or have any questions?

Here are 5 relative questions to expand on the topic:

  1. What is the SSS postulate and how is it used to prove triangle congruence?
  2. How does the CPCTC rule apply when proving angle congruence in triangles?
  3. What other methods can be used to prove triangles congruent besides SSS?
  4. Why is the reflexive property important in geometric proofs?
  5. How would you prove that two angles are congruent without using triangle congruence?

Tip: In geometry, always look for congruent triangles as a powerful tool for proving equal angles, sides, and other properties!

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Math Problem Analysis

Mathematical Concepts

Geometry
Congruence
Triangles
Circle Properties

Formulas

Reflexive property (AE = AE)
SSS (Side-Side-Side) Triangle Congruence
CPCTC (Corresponding Parts of Congruent Triangles are Congruent)

Theorems

SSS Triangle Congruence
CPCTC (Corresponding Parts of Congruent Triangles)

Suitable Grade Level

Grades 9-12