SOHCAHTOASOHCAHTOA recalls right-triangle ratios: Sine = Opposite/Hypotenuse, Cosine = Adjacent/Hypotenuse, Tangent = Opposite/Adjacent. Use a chosen acute angle, between 0° and 90°.
You’ll leave with these skills
01Tell when a right-triangle question needs a trig ratioUse the Pythagorean theorem when the question gives two sides and asks for the third, and a trig ratio when it gives an angle and a side.
02Draw the right triangle in a ladder, ramp, or shadow problemMark the corner where the wall, pole, or object meets the ground as the right angle, and label the slanted side as the hypotenuse.
03Find exact trig values for 30, 45, and 60 degreesDivide the sides of the 30-60-90 and 45-45-90 triangles on the reference sheet to get exact sine, cosine, and tangent values.
04Find a hypotenuse from an angle and the side across from itSet the sine of the angle equal to the opposite side over the hypotenuse, then divide the opposite side by the sine.
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