filmov
tv
Proof: Triangle Midsegment Theorem | Geometry, Proofs
Показать описание
The triangle midsegment theorem states that in a triangle, the segment joining the midpoints of any two sides of a triangle is half the length of the third side and parallel to the third side. This is a very neat result and not too tricky to prove. In today’s geometry lesson, we go over a proof of the triangle midsegment theorem!
To prove the triangle midsegment theorem, we use the SAS (side angle side) triangle similarity postulate, which tells us if two pairs of sides of two triangles are proportional (in the same ratio), and the included angles of these sides are congruent as well, then the triangles are similar. Remember that corresponding angles of similar triangles are proportional, and corresponding angles of similar triangles are congruent!
We also use the converse of the corresponding angles theorem in this proof. The converse of the corresponding angles theorem states that if two lines are cut by a transversal, and a pair of the resulting corresponding angles are congruent, then the lines are parallel.
I hope you find this video helpful, and be sure to ask any questions down in the comments!
+WRATH OF MATH+
Follow Wrath of Math on...
To prove the triangle midsegment theorem, we use the SAS (side angle side) triangle similarity postulate, which tells us if two pairs of sides of two triangles are proportional (in the same ratio), and the included angles of these sides are congruent as well, then the triangles are similar. Remember that corresponding angles of similar triangles are proportional, and corresponding angles of similar triangles are congruent!
We also use the converse of the corresponding angles theorem in this proof. The converse of the corresponding angles theorem states that if two lines are cut by a transversal, and a pair of the resulting corresponding angles are congruent, then the lines are parallel.
I hope you find this video helpful, and be sure to ask any questions down in the comments!
+WRATH OF MATH+
Follow Wrath of Math on...
Комментарии