Determine the interior angles of triangle ABC for a(5,1) b(4,-7) and c(-1,-8)
2 answers
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I will use AB for vector AB ... etc
AB=(-1,8)
AC=(-6,7)
AB•AC = |AB||AC|cosA
6+56 = √65√85cosA
cosA = 33.48°
Find a second angle the same way..
Use the 180° angle sum to find the third.
AB=(-1,8)
AC=(-6,7)
AB•AC = |AB||AC|cosA
6+56 = √65√85cosA
cosA = 33.48°
Find a second angle the same way..
Use the 180° angle sum to find the third.
1 answer