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# CA Geometry: Basic trigonometry

61-65, basic trigonometry. Created by Sal Khan.

## Want to join the conversation?

• what does theta mean cuz im confused HELP!
(1 vote)
• Theta is a Greek letter and it is usually used as a variable sometimes.
• what is that symbol next to the tangent at ?
(1 vote)
• If you mean the sign in the upper right hand corner next to tangent, that would be theta. Theta is a Greek letter used in trigonometry to represent a missing value.
• Where are these questions from?
(1 vote)
• In a triangle(right angled)if theeta is 30 degrees....how is cos theeta 1?
(1 vote)
• I agree that its impossible for the side to be three different lengths. ITs just not possible
(1 vote)
• i need help on trying to find the hypotmouse,adjacent ,and opposite so how put the answer in to the answer board
(1 vote)
• if a rectangle is 50 cm squared,what is the radius of each circle in the rectangle?
(1 vote)
• Which circles are you talking about. If you know the the circles then it would be 25/2/.
(1 vote)
• In what instances would we use the Pythagorean Theorem besides in the instances stated in this video?
(1 vote)
• I just wanted to know, who came up with this? HE must have been a genius.
(1 vote)
• For question 62, I think it is easier to use cos²+sin²=1 to get cos² then cos (as it will be positive).
Then you can get tan by using tan=sin/cos.
(1 vote)