Diagonals of a Rhombus: Ascertaining whether or not the triangles are congruent

Examples with solutions for Diagonals of a Rhombus: Ascertaining whether or not the triangles are congruent

Exercise #1

Given the rhombus:

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Are the triangles formed by the diagonal congruent?

Video Solution

Step-by-Step Solution

To determine if the triangles formed by the diagonals of a rhombus are congruent, we proceed with the following analysis:

Step 1: Understanding the properties of a rhombus

  • All sides of a rhombus are of equal length.
  • The diagonals of a rhombus bisect each other at right angles, meaning each diagonal divides the other into two equal parts.
  • The diagonals also form right triangles with each pair of adjacent sides.

Step 2: Applying congruency conditions

Consider the diagonals AC AC and BD BD that intersect at a point E E . The triangles of interest are ABE \triangle ABE , BCE \triangle BCE , CDE \triangle CDE , and DAE \triangle DAE .

Each diagonal is bisected by the other, meaning AE=EC AE = EC and BE=ED BE = ED . Because the diagonals intersect at right angles, each of these triangles is a right triangle.

By the Side-Side-Side (SSS) postulate of congruence:

  • AE=EC AE = EC
  • BE=ED BE = ED
  • The hypotenuse for each set of triangles is a side of the rhombus, which are equal by definition of a rhombus.

Step 3: Conclusion

Thus, all four triangles ABE \triangle ABE , BCE \triangle BCE , CDE \triangle CDE , and DAE \triangle DAE are congruent by SSS postulate, confirming that the triangles formed by the intersection of the diagonals in a rhombus are congruent.

Therefore, the statement that the triangles formed by the diagonals of a rhombus are congruent is True \text{True} .

Answer

True

Exercise #2

Given the rhombus:

BBBAAACCCDDD

Are the triangles formed by the diagonal congruent?

Video Solution

Step-by-Step Solution

To solve this problem, we need to determine if the triangles formed by the diagonals of a rhombus are congruent. A rhombus is a quadrilateral with all sides of equal length, and its diagonals intersect at right angles (90 degrees) and bisect each other. Due to this intersecting property, these diagonals divide the rhombus into four right-angled triangles.

Considering a rhombus with vertices labeled A A , B B , C C , and D D , where the diagonals intersect at point O O , such that AO=OC AO = OC and BO=OD BO = OD . Also, the sides AB=BC=CD=DA AB = BC = CD = DA due to the definition of a rhombus.

Now, let's focus on the triangles formed: - Triangle AOB \triangle AOB and Triangle COD \triangle COD .

We observe the following:

  • The side AB=CD AB = CD (since all sides of a rhombus are equal).
  • Both triangles AOB \triangle AOB and COD \triangle COD share the perpendicular diagonal AO=OC AO = OC (since the diagonals bisect each other).
  • The angle at the intersection (point O O is 90 degrees for both triangles due to the perpendicular nature of the diagonals).

Therefore, by the Side-Angle-Side (SAS) criterion for triangle congruence, these triangles are congruent because they have one side equal, an included right angle, and the other side equal. This analysis applies similarly to any other pair of triangles formed by the division of the rhombus by its diagonals.

Hence, the triangles formed by the diagonals of a rhombus are indeed congruent.

Therefore, the answer is True.

Answer

True

Exercise #3

Look at the rhombus below.

BBBAAACCCDDD

Are the four triangles overlapping?

Video Solution

Answer

Yes

Exercise #4

Given the rhombus:

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Are there six

congruent triangles?

Video Solution

Answer

Not true