Question

For the picture below: XY = 8, CD = 8. <X = 87 degrees, <Z=57 degrees, <D = 36 degrees and <B = 57 degrees.

Part 1. Explain how you can use the Triangle Sum theorem and the AAS congruency theorem to prove the two triangles congruent. (2pts)

Part 2. Write a correct congruency statement. You may use the = instead of the congruency symbol. (2pts)



(4 points)

Answers

There are no human answers yet.
Answered by GPT-4o mini
Let's break down the problem into the two parts requested:

### Part 1: Explanation of Congruence

To prove that the two triangles are congruent using the Triangle Sum Theorem and the AAS (Angle-Angle-Side) Congruency Theorem, follow these steps:

1. **Triangle Sum Theorem**: This theorem states that the sum of the angles in a triangle is always 180 degrees. We can use the known angles to find any missing angles in the triangles.
- For one triangle, we know two angles, \( \angle X = 87^\circ \) and \( \angle Z = 57^\circ \).
- We can find the third angle \( \angle Y \) using the Triangle Sum Theorem:
\[
\angle Y = 180^\circ - \angle X - \angle Z = 180^\circ - 87^\circ - 57^\circ = 36^\circ
\]
- The third angle \( \angle Y \) is found to be \( 36^\circ \).

2. **Using AAS Congruency Theorem**: We now have enough information to apply the AAS Congruency Theorem. This theorem states that if two angles and a non-included side of one triangle are congruent to two angles and a corresponding non-included side of another triangle, then the two triangles are congruent.
- In Triangle XYZ: \( \angle X = 87^\circ \), \( \angle Z = 57^\circ \), and side \( YZ = 8 \) (since we established CD = 8).
- In Triangle CDZ: \( \angle D = 36^\circ \) (which we found), \( \angle B = 57^\circ\), and side \( CD = 8 \).

Since we have established:
- \( \angle X = \angle D = 87^\circ \)
- \( \angle Z = \angle B = 57^\circ \)
- Side \( YZ = CD = 8 \)

With two angles and the side included being equal, we conclude that the triangles are congruent by AAS.

### Part 2: Congruency Statement

From the triangles we analyzed, we can write the congruency statement as follows:

\[
\triangle XYZ = \triangle DBC
\]

Both parts of the answer highlight the importance of angle and side relationships in proving triangle congruency using geometric theorems.