Find if point(lattitude,longtitude) is inside area - geolocation

Question

I have points(lat,long) coordindates and i have area leftTop(lat,long) rightBottom(lat,long) , i need to check if my points is inside area.
It's not correct just to check if point coordinate is more than leftLat, and less rightLat.
I have corners
leftLat=81.49021937827182
leftLng=38.979793936014175
rightLat=-0.5414380758487521
rightLng=173.9797962829470

Answer 1

function rayCrossesSegment($point, $a, $b)
{
$px = $point['lng'];
$py = $point['lat'];
$ax = $a['lng'];
$ay = $a['lat'];
$bx = $b['lng'];
$by = $b['lat'];
if ($ay > $by) {
$ax = $b['lng'];
$ay = $b['lat'];
$bx = $a['lng'];
$by = $a['lat'];
}
// alter longitude to cater for 180 degree crossings
if ($px < 0) {
$px += 360;
};
if ($ax < 0) {
$ax += 360;
};
if ($bx < 0) {
$bx += 360;
};
if ($py == $ay || $py == $by) {
$py += 0.00000001;
}
if (($py > $by || $py < $ay) || ($px > max($ax, $bx))) {
return false;
}
if ($px < min($ax, $bx)) {
return true;
}
$red = ($ax != $bx) ? (($by - $ay) / ($bx - $ax)) : INF;
$blue = ($ax != $px) ? (($py - $ay) / ($px - $ax)) : INF;
return ($blue >= $red);
}