randomQuadAngles.trapezoid()
randRange( 0, 3 )
ANSWER_POS % 2 === 0 ? ( ANSWER_POS + 3 ) % 4 : ( ANSWER_POS + 1 ) % 4
function() {
var a = ["", "", "", ""];
a[ANSWER_POS] = "x";
a[SHOWN_POS] = ANGLES[SHOWN_POS] + "^{\\circ}";
return a;
}()
What is the value of the angle marked with x?
init({
range: [ [-1, 12 ], [ -8, -1 ] ]
})
var q = new Quadrilateral([2, -7], ANGLES, randRange(0, 1) + 0.5, "");
q.boxOut( [ [ [ -0.5, -10 ], [ -0.5, 10 ] ] ], [ 0.1, 0 ] );
q.boxOut( [ [ [ 11.5, -10 ], [ 11.5, 10 ] ] ], [ -0.1, 0 ] );
q.draw();
q.labels = {
"angles": ANG_LABELS,
"sides": $.map($.map(q.sides, lineLength), function(x) {
return localeToFixed(x * 4, 1);
})
};
q.drawLabels();
ParallelLineMarkers((q.points[0][0] + q.points[3][0]) / 2, q.points[0][1]);
ParallelLineMarkers((q.points[1][0] + q.points[2][0]) / 2, q.points[1][1]);
ANGLES[ ANSWER_POS ]\Large{{}^\circ}
This figure is a trapezoid.
The angles of a trapezoid side are supplementary.
ANGLES[SHOWN_POS]^\circ + x = 180^\circ
x = 180^\circ - ANGLES[SHOWN_POS]^\circ
x = ANGLES[ANSWER_POS]^\circ
randomQuadAngles.isoscelesTrapezoid()
ANSWER_POS % 2 === 0 ? ( ANSWER_POS + 1 ) : ( ANSWER_POS - 1 )
This figure is an isosceles trapezoid.
The angles of bases of an isosceles trapezoid are equal.
Therefore, the angle x is also ANGLES[SHOWN_POS]^\circ
randomQuadAngles.parallelogram()
( ANSWER_POS + 2 ) % 4
This quadrilateral is a parallelogram.
Opposite angles of a parallelogram are equal.
Therefore, the angle x is also ANGLES[SHOWN_POS]^\circ
randomQuadAngles.parallelogram()
ANSWER_POS % 2 === 0 ? ( ANSWER_POS + 1 ) : ( ANSWER_POS - 1 )
This quadrilateral is a parallelogram.
Adjacent angles of a parallelogram are supplementary.
ANGLES[SHOWN_POS]^\circ + x = 180^\circ
x = 180^\circ - ANGLES[SHOWN_POS]^\circ
x = ANGLES[ANSWER_POS]^\circ
randomQuadAngles.rhombus()
init({
range: [ [-1, 12 ], [ -8, -1 ] ]
})
var q = new Quadrilateral( [ 2, -7 ], ANGLES, 1, "" );
q.boxOut( [ [ [ -0.5, -10 ], [ -0.5, 10 ] ] ], [ 0.1, 0 ] );
q.boxOut( [ [ [ 11.5, -10 ], [ 11.5, 10 ] ] ], [ -0.1, 0 ] );
q.draw();
q.labels = { "angles" : ANG_LABELS, "sides" : $.map( $.map( q.sides, lineLength ), function( x ){ return localeToFixed(x, 1); } ) };
q.drawLabels();
This quadrilateral is a rhombus, because it has all sides equal.
Opposite angles of a rhombus are equal.
Therefore, the angle x is also ANGLES[SHOWN_POS]^\circ
randomQuadAngles.rhombus()
ANSWER_POS % 2 === 0 ? ( ANSWER_POS + 1 ) : ( ANSWER_POS - 1 )
This quadrilateral is a rhombus, because it has all sides equal.
Adjacent angles of a rhombus are supplementary.
ANGLES[SHOWN_POS]^\circ + x = 180^\circ
x = 180^\circ - ANGLES[SHOWN_POS]
x = ANGLES[ANSWER_POS]^\circ
randomQuadAngles.kite()
randFromArray( [ 1, 3 ] )
( ANSWER_POS + 2 ) % 4
This quadrilateral is a kite, because it has two pairs of adjacent sides equal.
Angles between the non-equal sides of a kite are equal.
Therefore, the angle x is also ANGLES[SHOWN_POS]^\circ