// Numbas version: exam_results_page_options {"name": "Geometry: right-angled triangle", "extensions": [], "custom_part_types": [], "resources": [["question-resources/triangle_6nKlln9.png", "/srv/numbas/media/question-resources/triangle_6nKlln9.png"], ["question-resources/triangle_2.png", "/srv/numbas/media/question-resources/triangle_2.png"]], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"preamble": {"css": "", "js": ""}, "extensions": [], "rulesets": {}, "functions": {}, "tags": [], "variable_groups": [], "advice": "
Each angle on a triangle is connected to two sides and is facing another.
\nThe longest side of the triangle is always the hypotenuse.
\nThe other side that makes the angle is called the adjacent.
\nThe final side not connected in any way to the angle is called the opposite.
\nFor example, using the image below, you can see which side is denoted by each term from the highlighted angle's perspective.
\n\n\n\n\nOne of the ways you can approach this style of question is by using SOHCAHTOA.
\nThis can be written more visually as
\nIt represents each trigonometric function and what they are equivalent to.
\nWritten out in full, we would have:
\nSIN: opposite / hypotenuse
\nCOS: adjacent / hypotenuse
\nTAN: opposite / adjacent
\n\n\n\n\nFor example, $\\sin$ is represented by the first S.
\nIf we were given an angle, say of $30^\\circ$,
\n$\\sin(30^\\circ)=\\frac{\\text{opposite}}{\\text{hypotenuse}}$
\nEvaluating $\\sin(30^\\circ)=\\frac{1}{2}$, we now know that $\\frac{\\text{opposite}}{\\text{hypotenuse}}=\\frac{1}{2}$
\nIf we were given one of these sides, we would then be able to work out the other one by multiplying accordingly.
\n\n\n\nSimilarly if we were given two sides, and told to work out a specific angle, we could.
\nReferring to the image above, suppose we want to find the highlighted angle and we are given that the hypotenuse is equal to $5$ units, and the adjacent is $4$ units.
\nWe would determine from SOHCAHTOA that we need to use cos since we have the values for A and H.
\nSo, $\\cos(x)=\\frac{4}{5}$
\nHence, $x=\\cos^{-1}(\\frac{4}{5})=36.87^\\circ$
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", "type": "question", "contributors": [{"name": "Lovkush Agarwal", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/1358/"}]}]}], "contributors": [{"name": "Lovkush Agarwal", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/1358/"}]}