Enter two known values of a right triangle, such as two sides or one side and one angle, to calculate the missing side lengths or angles.
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This SOHCAHTOA calculator helps you find missing sides or angles of right triangles using the SOH.CAH.TOA method, providing step-by-step solutions.
SOH CAH TOA is a mnemonic way used to remember the formulas for main trigonometric ratios including sine (sin), cosine (cos), and tangent (tan).

Here is what the terms mean:
Formula:
sin(θ) = Opposite Hypotenuse
Explanation:
👉 Use the sine ratio to find unknown side lengths or angles when the opposite side and hypotenuse of a right triangle are known.
Formula:
cos(θ) = Adjacent Hypotenuse
Explanation:
👉 Use the cosine ratio when working with the adjacent side and the hypotenuse. This is useful for finding unknown sides or angles in right triangles.
Formula:
tan(θ) = Opposite Adjacent
Example:
tan(35°) = sin(35°) ÷ cos(35°) ≈ 0.7002
Explanation:
👉 You must use the tangent ratio when you know the opposite and adjacent sides of a right triangle. It is especially useful when the hypotenuse is not involved.
Follow these steps to use our SOHCAHTOA calculator accurately:
You can use SOHCAHTOA whenever you are working with a right triangle and know one acute angle and at least one side.
Here are some common real-world applications:
Follow these steps to work out the unknown sides of a right-angled triangle:
A right triangle has a hypotenuse of 13 cm and an acute angle (α) of 30°. Determine the length of the side opposite angle α
Solution:
Solution:
We are looking for the opposite side by having the hypotenuse, so use the SOH formula. Hence put the values and get to know the missing side.
Sin (30°) = Opposite 13 cm
We also know that Sin (30°) is a fixed value (0.5)
0.5 = Opposite 13 cm
Now, to find the missing opposite side, we can multiply both sides of the equation by 13 cm.
Opposite = 0.5 * 13 cm
Opposite = 6.5 cm
To save time and effort, try our trigonometry SOHCAHTOA calculator. It uses the SOHCAHTOA formulas to calculate the missing sides/angles of the right triangles.
It is easy to remember the sequence of Sin, Cos, and Tan. You need to try memorable phrases such as:
“Oscar Had A Heap Of Apples”:
It implies to right angle trig functions as:
Yes, it only works in the cases of right triangles. In non-right triangles, the side relationships(Hytoneous, Opposite, and Adjacent) do not hold. Therefore, it's not possible to apply SOCAHTOA to them.
Most of the students get wrong answer not because the formula is difficult, they apply the wrong side or angle in the formula:
Wrong: Choosing the side next to the angle as “opposite.”
Correct:
👉 Tip:
First of all, identify the angle first, and after that label the sides.
Wrong: Using the other acute angle in the triangle.
Correct: SOHCAHTOA is always based on the specific angle given in the problem.
Remember:
The “opposite” and “adjacent” sides change when the angle changes.
Wrong: Considering any long side as the hypotenuse.
Correct: The hypotenuse is always:
👉 Quick Check:
Find the 90° angle first and then the side across from it is the hypotenuse.
If you are unsure which side is the hypotenuse or need to calculate its length, try our Pythagorean Theorem Calculator before applying SOHCAHTOA.
Before calculating:
By keeping these points in mind, you can avoid the most common SOHCAHTOA mistakes and solve trigonometry problems more accurately.

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