8.2 Angles and Triangles - MRS. STATEMAN'S VIRTUAL...
17
8.2 Angles and Triangles p. 411
Transcript of 8.2 Angles and Triangles - MRS. STATEMAN'S VIRTUAL...
8.2 Angles and Triangles
p. 411
Acute Angle
O An angle whose measure is less than 90º
Obtuse Angle
O An angle whose measure is greater than 90º
Right Angle
O An angle whose measure is exactly 90º
Classify Triangles
By Angle Measure By Side Lengths
O Acute
O Obtuse
O Right
O Equilateral
O Isosceles
O Scalene
Acute Triangle
O An acute triangle has three acute angles (all
angles less than 90°)
Right Triangle
O A right triangle has one right angle
Obtuse Triangle
O An obtuse triangle has one obtuse angle
(one angle greater than 90°)
Equilateral Triangle
O An equilateral triangle has three congruent
sides.
Isosceles Triangle
O An isosceles triangle has two congruent
sides.
Scalene Triangle
O A scalene triangle has NO congruent sides.
Naming Geometric Figures
O A geometric figure can be named
using the vertices of each of its
angles. Use either a clockwise or
counterclockwise order such as
O Tick marks in a drawing show that
side lengths are equal. Arc marks
show than angle measures are equal.
Example 1
O Classify triangle XYZ by its angles
O Classify triangle XYZ by its side lengths
Triangles
O The sum of all three angles in a triangle is
always 180°
A
C B
∠𝐴 + ∠𝐵 + ∠𝐶 = 180°
Example 2A
O Find the value of x, then classify the triangle
by its angle measures.
Example 2B
O Find the value of x, then classify the triangle
by its angle measures.
Independent Practice p. 413 1-22, 28-32, 39-44
