The <u>perpendicular bisector</u> of a side of a triangle is a line perpendicular to the side and passing through its midpoint.
The <u>angle bisector</u> of an angle of a triangle is a straight line that divides the angle into two congruent angles.
A <u>median</u> of a triangle is a line segment drawn from a vertex to the midpoint of the opposite side of the vertex.
An <u>altitude</u> of a triangle is the perpendicular segment from a vertex of a triangle to the opposite side (or the line containing the opposite side).
(a) median
IG = IH ⇒ I is the midpoint GH, BUT it is not perpendicular to FI, so median
(b) angle bisector
m∠XYV = m∠ZYV, BUT YV is not perpendicular to XZ, so angle bisector
(c) altitude
m∠BDC = 90° but AD ≠ DC (so not perpendicular bisector)
Use the distance formula, AB=√[(1-(-9)]²+[(-1-(-3)]=√[100+4]=√104 use the same formula, AC=√52, BC=√52 AC²+BC²=52+52=104=AB² Yes, it is a right triangle.
