Answer:
Vertical
Step-by-step explanation:
They are vertical angles to each other
Answer:
Mark point E where the circle intersects segment BC
Step-by-step explanation:
Apparently, Bill is using "technology" to perform the same steps that he would use with compass and straightedge. Those steps involve finding a point equidistant from the rays BD and BC. That is generally done by finding the intersection point(s) of circles centered at D and "E", where "E" is the intersection point of the circle B with segment BC.
Bill's next step is to mark point E, so he can use it as the center of one of the circles just described.
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<em>Comment on Bill's "technology"</em>
In the technology I would use for this purpose, the next step would be "select the angle bisector tool."
Observation one
From the markings on the diagram <1 = 60o The left triangle is at least isosceles. Therefore equal sides produce equal angles opposite them.
Now we have accounted for 2 angles that are equal (each is 60 degrees) and add up to 120 degrees. The third angle (angle 2) is found from this equation.
<1 + 60 + <2 = 180 degrees. All triangles have 180 degrees.
60 + 60 + <2 = 180
Observation 2
<2 = 60 degrees.
120 + <2 = 180
m<2 = 180 - 120
m<2 = 60 degrees.
Observation 3
m<3 = 120
<2 and <3 are supplementary.
Any 2 angles on the same straight line are supplementary
60 + <3 = 180
<3 = 180 - 60
<3 = 120
Observation 4
m<4 = 40 degrees.
All triangles have 180 degrees. No exceptions.
m<4 + 20 +m<3 = 180
m<4 + 20 + 120 = 180
m<4 + 140 = 180
m<4 = 180 - 140
m<4 = 40
Answer:
ki yu mi kyu mi arigato nya ichi ni san nya arigato
