Предмет: Геометрия, автор: nirvana14

Пожалуйста прошу помогите)У меня между 2 и 3.От них зависит моя отценка. 1.отрезки AB, BC, CD последовательно отложены на одной прямой, AC=BD=18 см, BC=7 см. Найдите AD 2.найдите периметр треугольника,если 2 его угла равны,а 2 стороны имеют длины 20 см 10 см.

Ответы

Автор ответа: ATLAS
0

1. АВ=АС-ВС=18-7=11(см)

    АД=АВ+ВС=11+18=29(см)

 

2.Если нет чертежа, то в задаче два ответа -каждый к своему варианту расположения сторон.

Если два угла треугольника равны, то этот треугольник-равнобедренный. Это означает, что в нём боковые стороны равны.

Рассмотрим 1-ый вариант-эти стороны равны по 10 см, а основание равно 20 см. Тогда периметр Р=10+10+20=40(см)

Рассмотрим 2-ой вариант-эти стороны равны по 20 см, а основание равно 10 см.

Тогда периметр Р=20+20+10=50 (см)

 

Удачи!!!

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2. When at school we have our lessons 7 days a week.

3. Our classrooms are only on the third floor.

4. There are many specialized rooms for studying different subjects.

5. We have our classes of physical training in either our gymnasium or on the sport ground, situated in the parkю​