Download Triangle Angle Sum and Triangle Exterior Angle Theorem

yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Document related concepts
no text concepts found
Triangle Angle Sum Theorem, Triangle Exterior Angle
• State the triangle angle sum theorem and
solve for an unknown angle in a triangle
• Classify triangles based on measures of
angles as well sides
• State the triangle exterior angle theorem
and solve for an unknown exterior angle of
a triangle
Triangle Angle Sum Theorem
• The sum of the measures of the angles of
a triangle is 180°.
m∠A + m∠B + m∠C = 180
Ex: If m∠A = 30 and m∠B = 70;
what is m∠C ?
m∠A + m∠B + m∠C = 180
30 + 70 + m∠C = 180
100 + m∠C = 180
m∠C = 180 – 100 = 80
Classifying Triangles
Exterior and remote interior angles
• An exterior angle of a polygon
is an angle formed by a side
and an extension of an
adjacent side
• For each exterior angle of a
triangle, the two nonadjacent
interior angles are called the
remote interior angles
Triangle Exterior Angle Theorem
• The measure of each
exterior angle of a triangle
equals the sum of the
measures of its two remote
interior angles
m∠1 = m∠2 + m∠3
Ex: If m∠2 = 45 and m∠3 =
55, what is m∠1?
m∠1 = 45 + 55 = 100
Related documents