Cogito
Grade 8 Math · Chapter 3 · Lesson 1
Why Slope Is the Same Everywhere
The similar triangles you just built.
10 problems · about 19 minutes · 8.EE.B.6
Figure — use these to answer the problems
Warm-Up Review
From earlier lessons. Loosen up before the new work.
2 problemsFrom “Angle-Angle Similarity”
Angles 25° and 95°. What is the third?
AnswerFrom “Dilations on the Coordinate Plane”
(4, −3) dilated by 5. What is the new y?
Answer
Warm Up
Straightforward practice. Get the method working first.
4 problemsRise 12, run 4. Slope?
AnswerWhy is slope the same everywhere on a line?
- The slope triangles are similar, so their sides share one ratio.
- Because that is the definition.
Rise 10, run 5. Slope?
AnswerRise 3, run 6. Slope, as a decimal?
Answer
Build It Up
The same ideas with more to keep track of.
2 problemsFalls 9 over a run of 3. Slope?
AnswerWhat is the slope of a horizontal line?
Answer
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
2 problemsThe Slope
A line rises 6 for a run of 2. What is its slope?
AnswerGoing Down
A line falls 8 over a run of 4. What is its slope?
Answer