By definition, a right triangle will always have one angle that's 90 degrees, even if it's not labeled as such. So, you will always know at least one angle and can use trigonometry to find out the other 2 angles. The longest side of a triangle is called the “hypotenuse.” The “adjacent” side is adjacent (or next to) to the angle you're trying to determine. The “opposite” side is opposite to the angle you're trying to determine. Measure 2 of the sides so you can determine the measure of the remaining angles in the triangle. Plug your values into the equation: sine (x) = opposite ÷ hypotenuse. Say that the length of the opposite side is 5 and the length of the hypotenuse is 10. Divide 5 by 10, which is equal to 0.5. Now you know that sine (x) = 0.5 which is the same as x = sine-1 (0.5). If you have a graphing calculator, simply type 0.5 and press sine-1. If you don't have a graphing calculator, use an online chart to find the value. Both will show that x = 30 degrees. For this type of problem, use the equation: cosine (x) = adjacent ÷ hypotenuse. If the length of the adjacent side is 1.666 and the length of the hypotenuse is 2.0, divide 1.666 by 2, which is equal to 0.833. So, cosine (x) = 0.833 or x = cosine-1 (0.833). Plug 0.833 into your graphing calculator and press cosine-1. Alternatively, look up the value in a cosine chart. The answer is 33.6 degrees. The equation for tangent functions is tangent (x) = opposite ÷ adjacent. Say you know the length of the opposite side is 75 and the length of the adjacent side is 100. Divide 75 by 100, which is 0.75. This means that tangent (x) = 0.75, which is the same as x = tangent-1 (0.75). Find the value in a tangent chart or press 0.75 on your graphing calculator, then tangent-1. This is equal to 36.9 degrees.
याद रखें सभी समकोण त्रिभुज में एक कोण 90° के बराबर होता है: समकोण त्रिभुज की दो भुजाओं की लंबाई मापें: साइन फंक्शन का इस्तेमाल करें: कोसाइन फंक्शन का इस्तेमाल करें: टैन्जेंट फंक्शन का इस्तेमाल करें: