Given: `delta`abc prove: the sum of the interior angle measures of `delta`abc is 180°. what is the missing step in this proof?

Statement 3:.

Reason:Alternate Interior  Angles Theorem

Step-by-step explanation:

We are given that  a triangle ABC.

We have a proof  that the sum of interior angle measures pf triangle ABC is .

We have to find the missing steps in the given proof.

Statement 1 :Let  points A,B and C  form a triangle.

Reason: Given

Statement 2: is a line passing through B and parallel to with angles as labeled.

Reason: Definition a parallel line and labeling angles.

Statement 3:.

Reason:Alternate Interior  Angles Theorem

Statement 4:

Reason: Congruent angles have same measures

Statement 5

Reason: Angle addition and definition of a straight angle

Statement 6: [ytex]m\angle 1+m\angle 2+m\angle 3=180^{\circ}[/tex]

Reason : By substitution

Hence proved.

c.   x=2.4cm

step-by-step explanation:

similar triangles are triangles which have the same shape but not the same size. this means their angle measures are equal but their side lengths are not instead they are proportional. to solve, we will set up a proportion and solve.

a proportion is two equal ratios set equal to each other. we form the ratios by finding corresponding sides (sides which match to each other on both triangles by their position). out ratios will be one side of the small triangle over the corresponding side on the big triangle as shown below:

.

to solve the proportion, we'll cross multiply by multiplying numerator with denominator across the equal sign.