1.В равнобедренном треугольнике основание равно  12 см,а высота,проведенная к основанию 8 см.Найдите периметр треугольника.
2.Найдите значение выражения 7^-2/7^4*7^-9

Помогите пожалуйста,очень надо!Надо составить по этому тексту 5 вопросов Past Simple,а тему я не знаю,пожалуйста помогите:

Marie Curie was born in Warsaw on 7 November, 1867. Her father was a teacher of science and mathematics in a school in the town, and from him little Maria Sklodpwska - which was her Polish name - learned her first lessons in science. Maria's wish was to study at the Sorbonne in Paris, and after many years of waiting she finally left her native land in 1891. In Paris Maria began a course of hard study and simple living. She determined to work for two Master's degrees - one in Physics, the other in Mathematics. Thus she had to work twice as hard as the ordinary student. Yet she had scarcely enough money to live on. She lived in the poorest quarter of Paris. Night after night, after her hard day's work at the University, she got to her poorly furnished room and worked at her books steadily for hours. Sometimes she had no more than a bag of cherries. Though she was often weak and ill, she worked in this way for four years. She had chosen her course and nothing could turn her from it. Among the many scientists Maria met and worked with in Paris was Pierre Curie. Pierre Curie, born in 1859 in Paris, was the son of a doctor, and from early childhood he had been fascinated by science. At sixteen he was a Bachelor of Science, and he took his Master's degree in Physics when he was eighteen. When he met Maria Sklodowska he was thirty-five years old and was famous throughout Europe for his discoveries in magnetism. But in spite of the honour he had brought to France by his discoveries, the French Government could only give him a very little salary as a reward, and the University of Paris refused him a laboratory of his own for his researches. Pierre Curie and Maria Sklodowska, both of whom loved science more than anything else, very soon became the closest friends. They worked together constantly and discussed many problems of their researches. After little more than a year they fell in love with each other, and in 1895 Maria Sklodowska became Mme. Curie. Theirs was not only to be a very happy marriage but also one of the greatest scientific partnerships. Marie had been the greatest woman-scientist of her day but she was a mother too, a very loving one. There were their two little girls, Irene and Eve. By this time Mme. Curie had obtained her Master's degree in Physics and Mathematics, and was busy with researches on steel. She now wished to obtain a Doctor's degree. For this it was necessary to offer to the examiners a special study, palled a thesis. For some time Pierre Curie had been interested in the work of a French scientist named Becquerel. There is rare metal called uranium which, as Becquerel discovered, emits rays very much like X-rays. These rays made marks on a photographic plate when it was wrapped in black paper. The Curies got interested in these rays of uranium. What caused them? How strong were they? There were many such questions that puzzled Marie Curie and her husband. Here, they decided, was the very subject for Marie's Doctor's thesis. The research was carried out under great difficulty. Mme. Curie had to use an old store-room at the University as her laboratory - she was refused a better room. It was cold, there was no proper apparatus and very little space for research work. Soon she discovered that the rays of uranium were like no other known rays. Marie Curie wanted to find out if other chemical substances might emit similar rays. So she began to examine every known chemical substance. Once after repeating her experiments time after time she found that a mineral called pitchblende3 emitted much more powerful rays than any she had already found. Now, an element is a chemical substance which so far as is known cannot be split up into other substances. As Mme. Curie had examined every known chemical element and none of them had emitted such powerful rays as pitchblende she could only decide that this mineral must contain some new element. Scientists had declared that every element was already known to them. But all Mme. Curie's experiments pointed out that it was not so. Pitchblende must contain some new and unknown element. There was no other explanation for the powerful rays which it emitted. At that moment Pierre Curie stopped his own investigations on the physics of crystals and joined his wife in her effort to find those more active unknown chemical elements. Scientists call the property of giving out such rays "radioactivity", and Mme. Curie decided to call the new element "radium", because it was more strongly radioactive than any known metal. In 1903 Marie and Pierre together with Henry Becquerel were awarded the Nobel Prize in Physics. In 1911 Marie received the Nobel Prize in Chemistry. But the second prize went to her alone for in 1906 Pierre had died tragically in a traffic accident. Mme. Sklodowska-Curie, the leading woman-scientist, the greatest woman of her generation, has become the first person to receive a Nobel Prize twice. Marie lived to see her story repeated. Her daughter Irene grew into a woman with the same interests as her mother's and she was deeply interested in her mother's work. From Marie she learned all about radiology and chose science for her career. At twenty-nine she married Frederic Joliot, a brilliant scientist at the Institute of Radium, which her parents had founded. Together the Joliot-Curies carried on the research work that Irene's mother had begun. In 1935 Irene and her husband won the Nobel Prize for their discovery of artificial radioactivity. So, Marie lived to see the completion of the great work, but she died on the eve of the award.