today in geometry learning target: 6.6 you will calculate missing sides of triangles using...
DESCRIPTION
Write a proportion using Triangle Proportionality Theorem Substitute known values Cross MultiplyTRANSCRIPT
TODAY IN GEOMETRY…
Learning Target: 6.6 You will calculate missing sides of triangles using proportionality with parallel lines
Independent Practice
CH.6 TEST – WEDNESDAY/THURSDAY!
TRIANGLE PROPORTIONALITY THEOREM: If a line parallel to one side of a triangle intersects the other two sides, then it divides the two sides proportionally.
Given that:Then:
𝑄
𝑆
𝑅𝑇
𝑈 𝑅𝑇𝑇𝑄
𝑅𝑈𝑈𝑆
EXAMPLE: In the diagram, , what is length
9
𝑅
4
6𝑆
𝑇
𝑈𝑄
Write a proportion using Triangle Proportionality Theorem
Substitute known values
Cross Multiply
PRACTICE: Find length
2015
12𝑍𝑌
𝑈 𝑊
Write a proportion using Triangle Proportionality Theorem
Substitute known values
Cross Multiply
𝑋
CONVERSE OF THE TRIANGLE PROPORTIONALITY THEOREM: If a line divides two sides of a triangle proportionally, then it is parallel to the third side. Given that:
Then:𝑄
𝑆
𝑅𝑇
𝑈
EXAMPLE: Determine whether .
10𝑅
28
20𝑆
𝑇
𝑈𝑄
Write a proportion using Triangle Proportionality Theorem
Substitute known values
Cross Multiply
16
PRACTICE: Determine whether
13.5 22.5
12𝑍
𝑌
𝑈 𝑊
Write a proportion using Triangle Proportionality Theorem
Substitute known values
Cross Multiply
𝑋
20
EXAMPLE: Find length
4 18
𝑍
𝑈
Write a proportion using Triangle Proportionality Theorem
Substitute known values
Cross Multiply
𝑋
2𝑌
PRACTICE: Find length
13
𝑆
𝑄
𝑃
𝑥𝑅
7
15
PRACTICE: Use the diagram to find the value of each variable.
PRACTICE: Use the diagram to find the value of each variable.
HOMEWORK #6:
Pg. 400: 3-11, 13-17
If finished, work on other assignments:
HW #1 Pg. 360: 20-52 evenHW #2: Pg. 367: 3-12, 16-18HW #3: Pg. 376: 3-12, 23HW #4: Pg. 384: 3-14, 21-24, 26 (Graph paper needed)HW #5: Pg. 392: 3-12, 18-23