At a gathering of 30 people who all know each other and 10 people who know no one. people who know each other a hug, and people who do not know each other shakes hands. how many handshakes occur?

What is not true about kl and mn? what is mn? (show )

Amountain climber starts a climb at an elevation of 453 feet above sea level at his first rest stop he has climbed 162 feet and by his second rest stop he has climbed another 207 feet its getting late in the day so the climber starts his way down if the climber desends 285 feet how much does he need to ascend or descend to return to the original starting point

Opposite angles in a parrellelogram are