The hypotenuse of a 45°-45°-90° triangle measures 18 cm.

a) Dan's burning 4 calories per minute.

b) The slope of the graph is 1/4.

Why?

From the graph, we can see that every 1 minute, he is burning 4 calories. It can be deduced by looking at each of the points. For example, you can see that at 40 minutes, he burned 10 calories, at 80 minutes he burned 40 calories.

So:

Now, we must remember that the slope of a straight line is the rate of change. For this exercise, our line is used to show the number of calories burned per minute, so our slope is the rate of change between calories and minutes.

We can calculate the slope by dividing the height by the base of the triangles formed, for example, at 80 minutes (base) , Dan is burning 20 calories (height), so:

Therefore, the slope of the straight line in the graph is 1/4.

Have a nice day!