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# How do you prove that the diagonals in a rhombus divide the rhombus into four congruent triangles?

Updated: 4/28/2022

Wiki User

8y ago

The proof is fairly long but relatively straightforward. You may find it easier to follow if you have a diagram: unfortunately, the support for graphics on this browser are hopelessly inadequate.

Suppose you have a rhombus ABCD so that AB = BC = CD = DA. Also AB DC and AD BC.

Suppose the diagonals of the rhombus meet at P.

Now AB DC and BD is an intercept. Then angle ABD = angle BDC.

Also, in triangle ABD, AB = AD. therefore angle ABD = angle ADC.

while in triangle BCD, BC = CD so that angle DBC = angle BDC.

Similarly, it can be shown that angle BAC = angle CAD = angle DCA = angle ACB.

Now consider triangles ABP and CBP. angle ABP (ABD) = angle CBP ( CBD or DBC),

sides AB = BC

and angle BAP (BAC) = angle BCP (BCA = ACB).

Therefore, by SAS, the two triangles are congruent.

In the same way, triangles BCP and CPD can be shown to congruent as can triangles CPD and DPA. That is, all four triangles are congruent.

Wiki User

8y ago

Wiki User

8y ago

It is proven by the fact that a rhombus has 4 equal sides and that its diagonals intersect each other at right angles thus producing 4 congruent right angle triangles.

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Q: How do you prove that the diagonals in a rhombus divide the rhombus into four congruent triangles?
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Related questions

### In which parallelogram does the diagonal divide the parallelogram into two congruent right triangles?

It is a rhombus because its diagonals meet at right angles.

Yes

Yes.

Yes, they do.

### Can you show four identical right triangles in a rhombus?

Yes, draw the two diagonals. This will divide the rhombus into 4 identical triangles.

0.5

### Does the diagonals of a parallelogram bisect the angles?

No, the diagonals of a parallelogram do not necessarily bisect the angles. The diagonals of a parallelogram divide it into four congruent triangles, but they do not necessarily bisect the angles of those triangles.

### Which type of quarilateral has diagonals that will always divide it into four congruent triangles?

Only the square has.

### Where did the area of a rhombus come from?

If you multiply the lengths of the two diagonals, and divide by 2, you get the area of a rhombus. How does this work: Call the diagonals A &amp; B for clarity. Diagonal A will split the rhombus into 2 congruent triangles. Looking at one of these triangles, its base is the diagonal A, and its height is 1/2 of diagonal B. So the area of one of the triangles is (1/2)*base*height = (1/2)*A*(B/2) = A*B/4. The other triangle has the same area, so the two areas together make up the whole rhombus = 2*(A*B/4) = A*B/2.

A square.

### How do you calculate the area of a rhombus?

Multiply the diagonals and divide by 2

### Can you divide trapezioid into two congruent triangles?

A trapezoid can be divided into 2 triangles but they are not normally congruent to each other.