What is the length of the radius of the unit circle?
When the unit circle is drawn over an x- and y-axis it has some important coordinate points
What is the coordinate point at 90
Hint: Look at the image above.
Type your answer as an ordered pair
What is the coordinate point at 180° ?
Type your answer as an ordered pair
What is the coordinate point at 270° ?
Type your answer as an ordered pair
What is the coordinate point at 2
Type your answer as an ordered pair
We're going to be drawing triangles inside the unit circle, using the special angles of the unit circle.
These are the special angles of the unit circle:
Where else have you seen these angles?
Let's take a closer look at ONLY the 30
If we draw a vertical line from the edge of the circle down to the x-axis it creates a right triangle:
What is the measure of the missing angle at the top of the triangle?
If the radius of the unit circle is 1, what is the length of the hypotenuse of this triangle?
Now we need to find the two missing side lengths x and y using the 30-60-90 special right triangle ratios.
You cannot use sin or cos because we need exact fractions, no decimals!
Recall how to set up the table for 30-60-90
What is the exact value of x?
No decimal answers so you must use the table above!
What is the exact value of y?
No decimal answers so you must use the table above!
Let's find the other two! Which reference angle does the middle point in Q1 represent?
If we create a right triangle with the 45
Use the 45-45-90 table to find exact value of x.
No decimals and remember to rationalize the denominator!
Use the same table to find exact value of y.
No decimals and remember to rationalize the denominator!
Which reference angle does the last missing point represent?
If we create a right triangle with the 60
Notice that we have another 30-60-90 triangle, except the 30
List the values in order from least to greatest.
For example, the
The coordinate point for
What is the coordinate point for
When you list out the coordinate points in Quadrant III, what do you think will happen to the signs of the values?
The coordinate point for
What is the coordinate point for
The coordinate point for
What is the coordinate point for
Hint: think about if the x-value or y-value would be negative in Quadrant IV
Match the correct signs of each coordinate point
Quadrant I
Quadrant II
Quadrant III
Quadrant IV
The coordinate point for
What is the coordinate point for