## cpct full form in maths

The full name of CPCT in mathematics is “Corresponding Parts of Congruent Triangles”. It is a theorem that states that if two triangles are congruent, then their corresponding parts (sides and angles) are also congruent. This theorem is often used in geometric proofs and constructions.

### Step-by-step explanation of the CPCT theorem:

- Start with two triangles, ΔABC and ΔDEF, that are congruent to each other. This simply means that all the corresponding pairs of sides and angles are equal.
- Choose a pair of corresponding parts from the two triangles, such as side AB and side DE.
- Because the triangles are congruent, we know that side AB is equal in length to side DE (since they are corresponding parts).
- Choose another pair of corresponding parts, such as angle A and angle D.
- Again, because the triangles are congruent, we know that angle A is equal in measure to angle D (since they are corresponding parts).
- We can continue this process for all corresponding parts of the two triangles, including the remaining sides and angles.
- Therefore, we can conclude that all corresponding parts of congruent triangles are congruent, or CPCT for short. This means that if two triangles are congruent, then all of their corresponding pairs of sides and angles are equal in length and measure, respectively.

Overall, the CPCT theorem provides a useful tool for proving geometric congruences and for making geometric constructions with congruent triangles.

## What is a congruent triangle?

In geometry, two triangles are said to be congruent if they have the same size and shape. More formally, two triangles ΔABC and ΔDEF are congruent if and only if:

- All three pairs of corresponding sides are equal in length. That is, AB = DE, BC = EF, and AC = DF.
- All three pairs of corresponding angles are equal in measure. That is, ∠A = ∠D, ∠B = ∠E, and ∠C = ∠F.

When we say that two triangles are congruent, we can think of them as being identical copies of each other that have been translated, rotated, or reflected.

In other words, if we were to place one congruent triangle on top of the other, all of their corresponding parts (sides and angles) would match up perfectly.

### Importance of learning congruent triangles

Congruent triangles are important in geometry because they allow us to make conclusions about other geometric shapes and figures.

For example, if two triangles are congruent, then we can conclude that other pairs of corresponding parts (such as medians, altitudes, or bisectors) are also equal in length or measure, respectively.