Geo 8­3 lesson with notes 1st a.notebook
March 10, 2016
8­3 Special Right Triangles
Learning Targets:
I can use the properties of 45­45­90 triangles
I can use the properties of 30­60­90 triangles
What type of triangle is the highlighter?
Describe the height of the triangle.
What are the measures of the angles in the two triangles formed by the altitude fo the triangle?
Mar 6­1:22 PM
Mar 10­7:52 AM
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Geo 8­3 lesson with notes 1st a.notebook
March 10, 2016
Mar 10­7:59 AM
Mar 10­8:09 AM
2
Geo 8­3 lesson with notes 1st a.notebook
March 10, 2016
Mar 10­8:14 AM
Mar 10­8:16 AM
3
Geo 8­3 lesson with notes 1st a.notebook
March 10, 2016
The diagonal of a square makes two congruent isosceles right triangles, 45­45­90. Using the Pythagorean Theorem to solve for the hypotenuse, a pattern is found.
Mar 6­1:36 PM
45
45
Mar 6­1:41 PM
4
Geo 8­3 lesson with notes 1st a.notebook
March 10, 2016
Mar 6­1:46 PM
Example 1: Find x.
1. 3.
2.
4.
5.
Mar 6­1:46 PM
5
Geo 8­3 lesson with notes 1st a.notebook
March 10, 2016
Mar 6­1:50 PM
Example 2: Find x. 6.
7.
8.
Mar 6­1:51 PM
6
Geo 8­3 lesson with notes 1st a.notebook
March 10, 2016
The second special right triangle is 30­60­90.
Take an equilateral triangle and drop an altitude.
60
30
Mar 6­1:54 PM
Mar 6­2:21 PM
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Geo 8­3 lesson with notes 1st a.notebook
March 10, 2016
Mar 6­2:23 PM
Example 3: Find x and y.
8.
9.
10.
11.
Mar 6­2:24 PM
8
Geo 8­3 lesson with notes 1st a.notebook
March 10, 2016
Mar 6­2:28 PM
Example 4:
12. A quilt has the design shown in the figure, in which a square is divided into 8 isosceles right triangles. If the length of one side of the square is 3 inches, what are the dimensions of each triangle?
13. The top of the aquarium coffee table shown is an isosceles triangle. The table's longest side, AC, measures 107 centimeters. What is the distance from vertex B to side AC? What are the lengths of the other two sides? Mar 6­2:30 PM
9