Question 554559
help me figure out proofs involving triangles?
Given: m∠3 = m∠7
m∠2 = 60° 
m∠6 = 115°
<pre>
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red(line(-4.5,5.2,5.5,0), line(0,2.8,0,-6), line(0,-4,5.5,0), line(0,-6,5.5,0)),
locate(-.5,3,1), locate(.3,2.5,2), locate(4.5,.2,3), locate(3.4,-1.5,4),
locate(.3,-3.9,6), locate(.3,-3,5), locate(.1,-5,7)




 )}}}

Since m&#8736;2 = 60°, m&#8736;1 = 180°-60° = 120°

Since m&#8736;6 = 115°, m&#8736;5 = 180°-115° = 65°

That's all you wanted, but I'm going to find them all, since
no doubt you'll need to know how.

Since m&#8736;5 = 65° and m&#8736;2 = 60°, and angles 2,3, and 5 are interior angles
of the same triangle, and have sum 180°, then m&#8736;3 = 180°-65°-60° = 55°

m&#8736;7 = 55°, since we are given that m&#8736;3 = m&#8736;7

Since m&#8736;6 = 115° and m&#8736;7 = 55°, and angles 4,6, and 7 are interior angles
of the same triangle, and have sum 180°, then m&#8736;4 = 180°-115°-55° = 10°
(You got that one right, but you didn't need it to find m&#8736;5)

m&#8736;1 = 120°
m&#8736;2 = 60°
m&#8736;3 = 55°
m&#8736;4 = 10°
m&#8736;5 = 65°
m&#8736;6 = 115°
m&#8736;7 = 55°

Edwin</pre>