Cogito
Geometry · Chapter 7 · Lesson 1
Distance, Midpoint, and the Circle
Geometry done with coordinates.
10 problems · about 20 minutes · G-GPE.A.1, G-GPE.B.4, G-GPE.B.7
Figure — use these to answer the problems
Warm-Up Review
From earlier lessons. Loosen up before the new work.
2 problemsFrom “Tangents and Chords”
Radius 6, tangent 8. Distance to the centre?
AnswerFrom “Inscribed Angles”
Central 90°. Inscribed on the same arc?
Answer
Warm Up
Straightforward practice. Get the method working first.
4 problemsFrom (2, 3) to (10, 9). Distance?
AnswerWhat is the distance formula really?
- The Pythagorean theorem in coordinates.
- A new formula to memorise.
From (0, 0) to (6, 8). Distance?
AnswerFrom (1, 1) to (4, 5). Distance?
Answer
Build It Up
The same ideas with more to keep track of.
2 problemsFrom (3, 7) to (9, 11). Midpoint x-coordinate?
Answerx² + y² = 49. What is the radius?
Answer
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
2 problemsThe Distance
From (0, 0) to (3, 4). What is the distance?
AnswerThe Midpoint
From (2, 4) to (8, 10). What is the x-coordinate of the midpoint?
Answer