4.2 Congruent figures

Use statement when in doubt or on the shape the congruent sides and angles

Are not marked

Congruent triangles means

Congruent side lengths and angles In order Six parts

Use letters from the given congruency statement to see the

Corresponding parts or to determine if the triangles are congruent

When in proofs it says triangle blah is congruent to triangle blah then it is called

Definition of congruent triangles Proofs are pretty straightforward Definition of bisectors

The statement like triangle abb is congruent to triangle acc

Is in order Like if you did angle a you would have to say it is congruent to angle a Angles and sides have to be in order Like line segment ab is congruent to ac It has to follow same pattern from one shape to another Shapes are In same pattern as statement

The trick with lmnp is congruent to qrst is

It is not a triangle, the shape has four sides N-2*180 Use the statement to have the right order Also, in this problem you can pretty much see the congruent angles and sides without using the statement Use previous theorems

Congruent figures, not

Just triangles Though that is commonly what we are working with

Congruent Triangles/Polygons

Means that both the angles and sides have to be congruent All six parts of triangles have to be congruent

For corresponding parts it includes

Sides and angles

Congruent angles in order,

Sides with congruent angles in order

If it doesn't give you if any of the angles are congruent

Still always write it out using the statement, then see if it is true Even if its not given, you can sometimes still find it Use transversals + previous theorems TRANSVERSALS AND PARALLEL LINES

If two shapes are congruent,

That means all sides and angles

When n,aing the congruent parts,

The angles have to go in order from the image showing the congruency sign or the statement

Use previous theorems to prove why in

The concluding that the angles are congruent

For the proofs

Third angle theorem is common and so it va Given

Each pair of polygons are congruent. Find the measures of the numbered angles

This is very easy, it means exactly what it says The shapes are faced the same way or flipped around Can tell Can use transversals!

For listing congruent sides and angles when given triangle a is congruent to triangle b,

Use the statement or photo Go in order of sides and angles

If they don't show us if any of the sides are congruent on the diagram, then

We can't tell if the sides are actually congruent or not So, because not all six parts are congruent the triangles are not congruent Explain thoroughly

For concluding if the triangles are congruent and steps

Write down all the congruent sides and angles using the photo or statement Compare to the given triangle to see if what you wrote down is true Say what is true and why and what you can't find/isn't true SAY WHY All six parts have to be congruent

Find the valuables of the variables

Write equations using the info in the diagram and prior info that you know Like triangle sum theorem You know congruent angles and parts Also, congruent sides

Find the measures of the given angles or lengths of the given sides when given ABCD is congruent to FGHJ

Write it as like m of angle c equals the measurement of angle h which equals 70 It will give you congruent parts that you write as equal Read carefully This is not a triangle

For shapes where one of the vertexes is shared (triangles)

Write the angles on the outside which represent the vertex on the inside of the shape to make it easier Ssi

For proving two triangles congruent,

You have to prove that all six parts of sides and angles are congruent

When there are multiple angles, they share an angle

You have to say all three letters with the middle letter being the vertex So, you don't mix it up When it is by itself you can just say angle b