Как обозначают "Прямая AB перпендикулярна прямой CD"

составьте формулу для решения задачи периметр прямоугольника p дм а сумма двух противоположных сторон а дм.чему равна площадь прямоугольника

Запишите гидролиз соли сульфата меди.Пожалуйста очен нужно!

 Перевод.

Dear Sue,
It was great to hear that you are doing well in
your new town and I’m glad you like your new
neighbourhood. What’s it like where you live?
I miss you a lot too! But, you must have made
some new friends by now! What are they like?
Do your new friends love going to the cinema as
much as you do? Do they go to the same school
as you? And what about sports ― are your
friends as sporty as you are?
Well, I’ve got to go now. Mum’s calling me!
Best wishes,
Francine

My family has five members and we are all very
close. My mother, father, and grandmother
take good care of my little sister and myself.
Even though my parents work long hours, they
always find some time to spend with my sister
and me. We try to eat together every night
when it is possible. I am proud that I can talk
about anything with my parents and
grandmother. I really think my grandmother is
great, as she has lived such an interesting life
and always gives great advice. We all think
family is very important and enjoy spending
time together. We often go to the beach or for
a picnic on Sundays. We also play card games
together or spend an evening talking and
laughing. etc
What is your favourite thing to do with your
family? Are you closer to a particular family
member? Why? What is your relationship with
your sister like? etc