Найдите площадь треугольника abc, если угол a =30 гр. а высоты проведенные из вершин b и с, соответственно равны 5 и 8.Пожалуйста ребятки помогите)

ПОМОГИТЕ !!!!!!!!!!!! СРОЧНО!!!!!!!!!!!! БУДУ ВАМ ОЧЕНЬ БЛАГОДАРEН!!!!!!!!!! Choose the right answer.
1. I...get up very early day. I live near the school .
a.mustn/t    b.don/t have to c.     won/t have to
2.My mother is .... school teachher. a.a b.the c.-(nothing)
3.Look at the man ... is stahding in the corner.
a.who  b.which c.where
4.We need ... tomatoes . I/m going to the shop.
a.some b.any c.few
5.He is very popular and has .... friends .
a.many b.much c.a lot of
6.Everybody in our class ...... English .
a.like b.likes c.will likes
7.My parents don`t know......about Star Wars
a) nothing b) everything c) anything
8. Kate has a problem. Let ... talk to me about it
a) her b) him c) me
9.Last year our family ... to the sea.
a) went b) go c) is going
10.Who ... you do your homework yesterday?
a) helps b) helped c) help

упростите выражение: -3(4 – 2х) + 7(х - 2).

1)Where ... the children

a)am  b)is  c)are

2)John ... got a grey rabbit 

a)have  b)has

3)My little sister doesn't  ... a bike.

a) have  b) has

4)Ann ... her beautiful  flowers  every day.

a)water   b)waters

5)Does Tiny ... letters and postcards?

a)get   b)gets

6)When do the friends ... to bed?

a)go   b)goes

Дана трапеция АВСД, диагонали которой равны. Найдите периметр данной трапеции, если ее средняя линия равна 9, а боковая сторона АВ=4.