Let the coordinates of the circumcentre O of the triangle DEF be (x, y). Circumcentre of a triangle is equidistant from each of the vertices.
1. Distance OD=distance OE, then:
.
2. Distance OD=distance OE, then:
.
Solve the system:
,
,
.
Then
.
Answer: the coordinates of the circumcenter for ∆DEF are x=4.5, y=-1.
1. 6+n
2. n/2
3. n/4
4. seven less than a number
Answer:

Step-by-step explanation:
x=140°
m || n
Answer:
47 degrees
Step-by-step explanation:
A shape always adds up to 180 so I added the two degrees and subtracted it from 180. You get the answer 47
X+yz : is the answer to your question.