STEP 1: start by locating the x-axis representing the luminosity and put your left index finger on the value for your star. Let's look for a luminosity of 10^2 (This is circled in red on the y-axis)
STEP 2: locate the y-axis representing the temperature and put your right index finger on the value for your star. Let's look for a temperature of 20,000 (This is circled in blue on the x-axis)
STEP 3: begin sliding your left index finger to the right as you simultaneously slide your right index finger upward. Continue sliding your fingers in the designated directions until they cross paths.
STEP 4: the area that your fingers cross paths is where the classification of your star lies. Look at the region on the graph where your fingers have intersected and locate the label. As you can see in the picture below, the area where your two fingers should intersect is in the region labeled "Main Sequence".
See the image below for clarification of the directions.
