Transcript SD 3.2 Design Challenge II drawing triangles weik.pptx

Math CC7/8 – Be Prepared
On Desk:
1. Pencil
2. Math Journal
3. Learning Log
Learning Log:
• HW: p. 76 #6,7,8,9
• *SD Test next
Thursday. 9/24
(change)
Fundraiser – Keep selling!
Tasks for Today
• Summarize/Discuss last night’s HW
• SD Lesson 3.2
• Begin HW?
Last night’s HW!
Summarize lesson 3.1 – show example table
1. If the sum of 2 proposed side lengths is less than or
equal to the third side, no triangle can be constructed!
2. In NO case can a given set of side lengths be used to
make 2 different triangle shapes!
3. Do make a triangle: (5, 12, 8), (16, 10, 7), (6, 3, 6)
4. Do NOT make a triangle: (4, 9, 3), (12, 5, 19), (11, 5, 18)
Launch video 3.2
These SSA won’t create a
unique triangle, but some
such combinations will.
AAA won’t make a congruent
triangle, the side lengths may
be different.(similar triangle)
AAS will make a unique triangle
because we know the third angle
must be 180-106 degrees. (ASA
situation)
Use labsheet 3.2B
• Draw an equilateral triangle
with sides 1 inch. SSS
• Draw an angle of 60 degrees
and mark 2 sides of 1 inch
on the legs of that angle. SAS
Then connect the end points.
• Draw a right triangle with SAS
legs 1 inch and 1.25 inches.
• Draw an angle of 90 degrees
and mark sides of 1 in. and
1.25 in on the legs of that
angle. Then connect the end
points. SAS
Use labsheet 3.2B
• You need to give either 2 sides
and the included angle, or 2
angles and the side. SAS ASA
• Angles = 30, 125, 25 degrees
• Sides = 1.25, 1.25, and 2.5
inches
• Draw an isosceles triangle
with vertex angle 40
degrees and equal sides
SAS
1.5 in long.
• Draw an isosceles triangle
with base 1 in. long and
base angles 70 degrees. ASA
You need at least 3 sides and/or angle
measurements, but not ANY three.
• Given SSS - there will only be one triangle.
• Given 2 angles and one side length (either the
included side (ASA) or the nonincluded side
(AAS)), there will be only ONE triangle.
All copies of the right triangle using the same 3 sides
lengths will make the same triangle.
The order in which you connect the sides does NOT
matter. So, the copy will also be a right triangle.