Suppose triangle ABC is right angled at C. Suppose you are given that the angle at B is theta. Then
if you know the length of AB (the hypotenuse), then
BC = AB*cos(theta) and
AC = AB*sin(theta)
if you know the length of BC, then
AB = BC/cos(theta) and
AC = BC*tan(theta)
if you know the length of AC, then
AB= AC/sin(theta) and
BC = AC/tan(theta)
When placed next to any angle on a triangle, the theta symbol (θ) represents that missing angle.
The cosine of theta is adjacent over hypotenuse, given a right triangle, theta not being the 90 degree angle, adjacent not being the hypotenuse, and theta being the angle between adjacent and hypotenuse. In a unit triangle, i.e. in a unit circle circumscribed with radius one, and theta and the center of the circle at the origin, cosine of theta is X.
SOH CAH TOA is a way of remembering what the functions sin, cos, & tan mean in a right angle triangle. With a triangle with one of the acute angles labelled (theta) the longest side H (Hypotenuse), the side opposite the labelled angle O, and the short side closest to the angle A (Adjacent) SOH ->SIN(Theta)=0/H CAH ->COS(Theta)=A/H TOA ->TAN(Theta)=O/A
Theta is just a Greek letter used to denote measurement of angle. Sine is a trigonometric function, i.e., the ratio of the side opposite to the angle theta to the hypotenuse of the triangle. So Sine theta means the value of sine function for angle theta, where theta is any angle.
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when you have a right triangle and one of the two non-right angles is theta, sin(theta) is the side of the triangle opposite theta (the side not touching theta) divided by the side that does not touch the right angle
The sine theta of an angle (in a right triangle) is the side opposite of the angle divided by the hypotenuse.
The sine of an angle theta that is part of a right triangle, not the right angle, is the opposite side divided by the hypotenuse. As a result, you could determine the hypotenuse by dividing the opposite side by the sine (theta)...sine (theta) = opposite/hypotenusehypotenuse = opposite/sine (theta)...Except that this won't work when sine (theta) is zero, which it is when theta is a multiple of pi. In this case, of course, the right triangle degrades to a straight line, and the hypotenuse, so to speak, is the same as the adjacent side.
In a Right Triangle SINE Theta is equal to the: (Length of opposite side) / (Length of Hypotenuse).
Tangent (theta) is defined as sine (theta) divided by cosine (theta). In a right triangle, it is also defined as opposite (Y) divided by adjacent (X).
The answer depends on what theta represents!
You can use your trigonometric functions (sine, cosine, and tangent).
They are mathematical functions. Most people are introduced to them as trigonometric functions. In the context of a right angled triangle, with one of its angles being theta, Cos(theta) = The ratio of the lengths of the adjacent side and the hypotenuse. Sin(theta) = The ratio of the lengths of the opposite side and the hypotenuse. More advanced mathematicians will know them simply as the following infinite series: Cos(theta) = 1 - x2/2! + x4/4! - x6/6! + ... and Sin(theta) = x/1! - x3/3! + x5/5! - x7/7! + ... n! = 1*2*3* ... *n
When placed next to any angle on a triangle, the theta symbol (θ) represents that missing angle.
The cosine of theta is adjacent over hypotenuse, given a right triangle, theta not being the 90 degree angle, adjacent not being the hypotenuse, and theta being the angle between adjacent and hypotenuse. In a unit triangle, i.e. in a unit circle circumscribed with radius one, and theta and the center of the circle at the origin, cosine of theta is X.
If X and Y are sides of a right triangle, R is the hypoteneuse, and theta is the angle at the X-R vertex, then sin(theta) is Y / R and cosine(theta) is X / R. It follows, then, that X is R cosine(theta) and Y is R sin(theta)
The answer depends on how the ratios are defined. In some cases tan is DEFINED as the ratio of sine and cosine rather than from the angle in a right angled triangle.If the trig ratios were defined in terms of a right angled triangle, thensine is the ratio of the opposite side to the hypotenuse,cosine is the ratio of the adjacent side to the hypotenuse,and tangent is the ratio of the opposite side to the adjacent side.It is then easy to see that sin/cos = (opp/hyp)/(adj/hyp) = opp/adj = tan.If sine and cosine are defined as infinite sums for angles measured in radians, iesin(x) = x - x^3/3! + x^5/5! - x^7/7! + ...andcos = 1 - x^2/2! + x^4/4! - x^6/6! + ...then it is less easy to see tan = sin/cos.