The missing steps are each right angles and
.
Solution:
Step 1: Given data:



Step 2: In the two polygons,
and 
(Each right angle)
Step 3: Given

Step 4: By third angle theorem,
If two angles in one triangle are congruent to the two angles in the other triangle, then the third angles in the triangles also congruent.

Step 5: By the definition of congruent polygons,
If two same shape polygons have all the angles are congruent and all the corresponding sides are congruent then the polygons are congruent.
Hence
.
Therefore the missing steps are each right angles and
.
Answer:
d) intersecting, but not perpendicular lines
Step-by-step explanation:
Changing the sign of one of the variable terms causes the line to be reflected across one of the axes. The slope is the opposite of what it was. Since the original slope was not 1 or -1, the resulting line is not perpendicular to it. Lines with different slopes will be intersecting.
The two lines are intersecting, but not perpendicular.
Answer:

Step-by-step explanation:
A circumference of a circle can be determined by this: 2*pi*r
We're given the diameter. Divide that by 2 to get the radius.
6.45/2 = 3.225
Now multiply that by 2*pi. That gives us 2 * 3.14 * 3.225 = 20.253.
This could've also been done easier by doing pi*d where d is the diameter and you give the answer by multiplying them both. Also works, but the above formula is just key to many things and can also be used to derive the simpler one. Hope it helps! :)
Answer:
there are 20 different combinations if that was the question.
Step-by-step explanation:
Formula :
Combination(event 1) times Combinations (Event2)