# Lesson 1

How Well Can You Measure?

Let’s see how accurately we can measure.

### Problem 1

Estimate the side length of a square that has a 9 cm long diagonal.

### Problem 2

Select **all** quantities that are proportional to the diagonal length of a square.

A:

Area of the square

B:

Perimeter of the square

C:

Side length of the square

### Problem 3

Diego made a graph of two quantities that he measured and said, “The points all lie on a line except one, which is a little bit above the line. This means that the quantities can’t be proportional.” Do you agree with Diego? Explain.

### Problem 4

The graph shows that while it was being filled, the amount of water in gallons in a swimming pool was approximately proportional to the time that has passed in minutes.

- About how much water was in the pool after 25 minutes?
- Approximately when were there 500 gallons of water in the pool?
- Estimate the constant of proportionality for the gallons of water per minute going into the pool.