Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with
or
.
Download ZIP
Fetching contributors…

Cannot retrieve contributors at this time

81 lines (73 sloc) 3.501 kB
<!DOCTYPE html>
<html data-require="math graphie angles interactive">
<head>
<title>Measuring angles</title>
<script data-main="../local-only/main.js" src="../local-only/require.js"></script>
</head>
<body>
<div class="exercise">
<div class="vars">
<var id="ANGLE_ONE">randRange(0, 359)</var>
<var id="DIFF">10 * randRange(1, 18)</var>
</div>
<div class="problems">
<div>
<p class="question">
Measure this angle in degrees.
</p>
<p class="render-answer-area-here"></p>
<div class="problem">
<div class="graphie" id="angle">
var LENGTH = 9;
var ANGLE_TWO = ANGLE_ONE + DIFF;
var ANGLE_ONE_R = ANGLE_ONE * PI / 180;
var ANGLE_TWO_R = ANGLE_TWO * PI / 180;
init({
range: [ [-11, 15], [-10, 10] ],
scale: 20
});
style({ stroke: BLUE, arrows: "--&gt;" });
line([0, 0], [LENGTH * cos(ANGLE_ONE_R), LENGTH * sin(ANGLE_ONE_R)]);
line([0, 0], [LENGTH * cos(ANGLE_TWO_R), LENGTH * sin(ANGLE_TWO_R)]);
style({ stroke: BLUE, arrows: null });
arc([0, 0], 1, ANGLE_ONE, ANGLE_TWO);
addMouseLayer();
graph.protractor = protractor([14, -8]);
graph.showOrigin = function() {
graph.protractor.moveTo( 0, 0 );
};
graph.showCorrect = function() {
graph.showOrigin();
graph.protractor.rotateTo(540 - ANGLE_ONE - DIFF);
};
</div>
</div>
<div class="solution" data-type="multiple">
<span class="sol" data-forms="integer" data-inexact="" data-max-error="5"><var>DIFF</var></span><code>{}^{\circ}</code>
</div>
</div>
</div>
<div class="hints">
<p>
First, align the origin of the protractor with the vertex of the angle.
<button onclick="javascript:
KhanUtil.currentGraph.graph.showOrigin();
">Show me</button>
</p>
<p>
Next, rotate the protractor so that the <code>0^{\circ}</code> mark lines up with one side of the angle.
<button onclick="javascript:
KhanUtil.currentGraph.graph.showCorrect();
">Show me</button>
</p>
<div>
<div class="graphie" data-update="angle">
graph.showCorrect();
label([10 * cos(toRadians(ANGLE_ONE)), 10 * sin(toRadians(ANGLE_ONE))], "\\pink{" + DIFF + "^{\\circ}}" );
</div>
<p>The angle is <code><var>DIFF</var></code> degrees.</p>
</div>
</div>
</div>
</body>
</html>
Jump to Line
Something went wrong with that request. Please try again.