applying polygon properties to coordinate geometry 6.7 – 6.8
TRANSCRIPT
Our Goals:
To apply previously learned coordinate geometry formulas Coordinate Midpoint Formula Distance Formula
Our Goals:
To apply previously learned coordinate geometry formulas Coordinate Midpoint Formula Distance Formula Slope
Our Goals:
To apply previously learned coordinate geometry formulas Coordinate Midpoint Formula Distance Formula Slope
To the properties of polygons and quadrilaterals discussed in Chapter 6 thus far.
If forgotten, these are on page 400 in your book!
To apply previously learned coordinate geometry formulas Coordinate Midpoint Formula Distance Formula Slope
To the properties of polygons and quadrilaterals discussed in Chapter 6 thus far.
To start
Let’s talk about the classification of triangles If we do so by sides, how can we figure out side lengths?
Scalene, Isosceles, Equilateral Let’s talk about the classification
of triangles If we do so by sides, how can we figure out side lengths?
To start
Let’s talk about the classification of triangles If we do so by sides, how can we figure out side lengths?Distance Formula
Page 401
Let’s talk about the classification of triangles If we do so by sides, how can we figure out side lengths?Distance Formula
You try this one
Classify HJK by its sides given the coordinates H(-1,0), J(-16, -20) and K(-25, 7).
You try this one
Classify HJK by its sides given the coordinates H(-1,0), J(-16, -20) and
K(-25, 7).
25
20
15
10
5
-5
-10
-15
-20
-25
-50 -40 -30 -20 -10 10 20 30 40 50
J
K
H
Can we ever do it without doing all 3 sides?
Classify HJK by its sides given the coordinates H(-1,0), J(-16, -20) and
K(-25, 7).
25
20
15
10
5
-5
-10
-15
-20
-25
-50 -40 -30 -20 -10 10 20 30 40 50
J
K
H
Now for quadrilaterals
Can we do some of them with sides? Sure, but it is going to be a lot easier with slopes, since many of our classifications involve parallel and perpendicular properties.
Here’s a procedure checklist… 1) Find the slopes of all 4 sides.
No equal slopes Quadrilateral.
One pair = Trapezoid
Here’s a procedure checklist… 1) Find the slopes of all 4 sides.
No equal slopes Quadrilateral.
One pair = Trapezoid Both pairs = Parallelogram.
Here’s a procedure checklist… 2) If AND only if you have a
trapezoid, find the lengths of the 2 non-parallel sides using the distance formula to see if it’s isosceles.
Here’s a procedure checklist… 2) If AND only if you have a
trapezoid, find the lengths of the 2 non-parallel sides using the distance formula to see if it’s isosceles.
3) If it’s a parallelogram, see if the slopes are negative reciprocals.
Here’s a procedure checklist… 2) If AND only if you have a
trapezoid, find the lengths of the 2 non-parallel sides using the distance formula to see if it’s isosceles.
3) If it’s a parallelogram, see if the slopes are negative reciprocals.
Rectangle
Here’s a procedure checklist… 3) If they’re not negative
reciprocals, check the slopes of the diagonals.
Here’s a procedure checklist… 3) If they’re not negative
reciprocals, check the slopes of the diagonals. If the slopes of the diagonals are negative reciprocals Rhombus
Here’s a procedure checklist… 4) Even if the slopes are
negative reciprocals, you are checking the slopes of the diagonals.
Here’s a procedure checklist… 4) Even if the slopes are
negative reciprocals, you are checking the slopes of the diagonals. Rectangle with perpendicular
diagonals is a square.