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Chapter 4 . 4-3 Angle Relationship in triangles. SAT Problem of the day . solution. Right Answer: A. Objectives. Find the measures of interior and exterior angles of triangles. Apply theorems about the interior and exterior angles of triangles. sum of the interior angles of a triangle.
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Chapter 4 4-3 Angle Relationship in triangles
solution Right Answer: A
Objectives Find the measures of interior and exterior angles of triangles. Apply theorems about the interior and exterior angles of triangles.
sum of the interior angles of a triangle • Do you know what is an interior angle of a triangle? • Answer: They are the angles in the inside of a triangle • Do you know what is an exterior angle of a triangle? • Answer: they are the angles form in the outside of a triangle • Who much do all the interior angles of a triangle add up? • Answer: they add up to 180 degrees
What is an auxiliary line? • An auxiliary line is a line that is added to a figure to aid in a proof.
Example#1 • Use the diagram drawn below to find mXYZ
Example#2 • Use the diagram drawn below to find mYWZ.
Example#3 • Use the diagram to find mMJK.
Student guided practice • DO problems 1- 4 in the worksheet and 4 and 5 in your book page 235
What is a corollary? • A corollary is a theorem whose proof follows directly from another theorem. Here are two corollaries to the Triangle Sum Theorem.
Example#4 • One of the acute angles in a right triangle measures 2x°. What is the measure of the other acute angle?
Example#5 • The measure of one of the acute angles in a right triangle is 63.7°. What is the measure of the other acute angle?
Student guided practice • Do problems 6 to 8 in your book page 235
Angle relationship • The interior is the set of all points inside the figure. The exterior is the set of all points outside the figure. Exterior Interior
Angle relationship • An interior angle is formed by two sides of a triangle. An exterior angle is formed by one side of the triangle and extension of an adjacent side. Interior angle <3 and exterior angle <4
Angle relationship • Each exterior angle has two remote interior angles. A remote interior angle is an interior angle that is not adjacent to the exterior angle. • The remote interior angles of 4 are 1 and 2.
Example#6 • Find mB.
Example#7 • Find mACD.
Student guided practice • Do problems 9 and 10 in your book page 235
Example#8 • Find mK and mJ
Example#9 • Find mP and mT.
Student Guided practice • Do problems 12 and 13 in your book page 235
Homework!!! • Do problems 16-22 in your book page 236
Closure • Today we learned about angles of triangles • Next class we are going to learn about congruent triangles