4-1+Triangles+and+Angles

4-1 Triangles and Angles

===In this section, it teaches you the names and classifications of triangles. The first goal, will show you how classify triangles by their sides and angles. The second goal of this section will teach you how to find the angles measures in triangles.===

Definitions:
Triangle : A plane figure with three straight sides and three angles Vertex : 3 points that connect two sides together Adjacent sides : two sides connected to the same vertex Legs (of right angle) : the two sides that form a right angle Hypotenuse : The longest side of a right triangle, opposite the right angle. Legs (of isosceles triangle with only 2 congruent sides) : the two congruent sides Base : the third side of the isosceles triangle Interior angles : the three angles in a triangle Exterior angles : the angle between one side of a triangle and the extension of an adjacent side Corollary to a theorem : a theorem that is easily proved from the first


 * Here are some sample problems. **

**Names of Triangle** : __ Classification by sides = __ Equilateral: 3 congruent sides

Isosceles: at least 2 congruent sides

Scalene: No congruent sides

__ Classification by Angles = __ 3 acute angles

3 congruent angles 1 right angle 1 obtuse angle

__Classifying Triangles__

Link to Theorems: 

Practice Review

m<b = 29 m<c = 36 Find the measure of angle A and state what theorem you used

Select the right name for the following triangle: right isosceles, acute scalene, obtuse isosceles, acute isosceles, right scalene

Classify the triangle in the most detailed way possible

Find the value of x and find the missing measures.

Links to Educational websites: [|How to classify Triangles] [|Angle Sum Theorem] [|Exterior angles theorem] [|Triangle sum with proof]