Четырех угольник abcd задан координатами вершин a (1; 4) b (3; 5) c (9; 1) d (7; 5) a) докажите что abcd - не паралелограмм б) найдите периметр abcd

Если треугольник правильный, то все стороны, соответственно равны. Пусть сторона треугольника будет а. Найдём площадь треугольника через вписанную окружность: S-рxr, гдер-полупериметр треугольника, а r - радиус окружности. Найдём полупериметр треугольника по формуле: P3 (а+b+c)/2 Так как по условию задачи радиус вписанной окружности равен 8 см, и все стороны треугольнин равны, то: P- (a+btc)/2 За/2 Тогда S %3D рхr %3D За/2x8-24a/2 - 12а По условию радиус вписанной окружности 8 см. Сторона правильного треугольника выводится из формулы вписанной окружности: r %3D V3/6*a а%3D 16V3 S312a %3D 1216 V3 %3D 192V3 см? ответ: 192VЗ см?

Last year, my husband Mike and I decided to visit New Zealand. We wanted to tour the

country, but we both hate long car journeys. The travel agent suggested a 13-day coach trip. It was a

good price, so we booked it with our plane tickets. We made a good choice. The coach journeys passed

quickly and our driver told us about each place. We learned a lot from him. We flew from London to

Christchurch and had a free day there before the coach trip started. We were not at all tired, so we

walked round the city from morning till night. It had good museums, many restaurants and lovely

shops. The best place we visited on the trip was Queenstown. You can choose to do almost anything,

from sailing to climbing. We had three days there, but it was not enough. All the hotels were good. My

favourite one was the Puka Park Lodge. It was on a hill above a beach and there were trees

everywhere. We woke up and listened to the birds singing. Now, when we are eating breakfast at home

and we hear the noise of the traffic, we think of those beautiful mornings in New Zealand!