Exact Trig Values Using the Hand Trick

Lucy introduces a hand trick to easily find exact trigonometric values for angles 0°, 30°, 45°, 60°, and 90°. By associating each finger with an angle, students can calculate sine, cosine, and tangent values using simple finger counting and square root operations. This method provides an alternative to memorizing trigonometric tables, making it easier to remember and apply these values.

Which finger represents the 30-degree angle?

• Index finger

• Little finger

• Thumb

• Ring finger

How do you calculate the sine of 30 degrees using your hand?

• 1

• Square root of 3 divided by 2

• Square root of 1 divided by 2

• Square root of 2 divided by 2

What is the sine of 90 degrees?

• 1

• 1/2

• Square root of 2 divided by 2

• 0

How do you find the sine value for an angle using your hand?

• Count fingers above the bent finger

• Count fingers below the bent finger

• Flip your hand over

• Square root the number of fingers not bent

How is the cosine of 60 degrees found using the hand trick?

• Square root of 3 divided by 2

• 1

• Square root of 1 divided by 2

• 0

What value does cosine of 90 degrees equal to?

• 1

• Square root of 1 divided by 2

• 0

• Square root of 3 divided by 2

What is the general method for finding cosine values with the hand trick?

• Square root the number of fingers bent

• Count fingers below the bent finger

• Count fingers above the bent finger

• Flip your hand over and count

For finding tan values, in which direction do you flip your hand?

• Over

• Upwards

• To the right

• To the left

What is the tan of 60 degrees?

• 1

• Square root of 3

• 0

• Square root of 1 divided by square root of 3

What is the simplified value of tan 30 degrees?

• 1 over square root of 3

• Square root of 3

• 1

• 0