Предмет: Математика, автор: ForceMaestro

Дана трапеция.
AB=CD
угол CDA равен 30 градусов
CD=10
BC=8
Найти площадь трапеции.

Гимнаст44rus: AB и CD это основания?

Ответы

Автор ответа: Аноним
1
С треугольника CDK(\angle CKD = 90а):\,\,KD=CD\cdot \cos30=5 \sqrt{3}
CK=CD\cdot \sin30=5

основания AD = BC + 2 KD = 8+10√3

S= \frac{8+10 \sqrt{3}+8 }{2} \cdot5=40+25\sqrt{3}

Ответ: 40+25\sqrt{3}.
Приложения:
Предыдущий вопрос
Следующий вопрос
Похожие вопросы
Предмет: Английский язык, автор: annagolubeva2004
ПОЖАЛУЙСТА ПОМОГИТЕ!!!
Complete the gaps with the verbs from the brackets in Past Simple, Past Continuous or Past Perfect.
1. I __________ (walk) down the street yesterday, when I __________ (saw) a girl who __________ (cry). When I __________ (ask) her why she __________ (cry), she __________ (tell) me that she __________ (lose) her parents and that she __________ (be) very afraid.
2. Mary __________ (move) out of her parents’ house three years before her father __________ (decide) to sell it. However, when she __________ (learn) about her father’s decision, she __________ (feel) sad. Nevertheless, she understood that her parents __________ (get) older and that they __________ (not/need) such a big house anymore.
3. It __________ (be) 11 pm and John Bishop __________ (sit) in the bushes outside the Browns’ residence. He __________ (prepare) his plan two days earlier. When he __________ (see) Mr and Mrs Brown leaving the house, he __________ (jump) out of the bushes and __________ (run) to the door. He __________ (pick) the lock and __________ (go) inside. Unfortunately for him, an angry pit bull __________ (wait) in the hall.
4. My dad always __________ (hate) my boyfriend, Jim. However, when we __________ (decide) to move in together, he __________ (call) me and __________ (say) that he __________ (never/like) him, but he __________ (trust) my judgement. It’s funny, because when he __________ (call) me, Jim and I __________ (argue).
5. Daniel is a very nice person now, but he __________ (be) different several years ago. He __________ (spend) time with a gang of rough boys, __________ (steal) radios from parked cars, and __________ (get) into fights very often. However, one day when he __________ (walk) home, he __________ (meet) a beautiful girl from a Catholic school. After he __________ (meet) her, he __________ (change) for her completely.
6. When I __________ (be) a little boy, I __________ (have) a dog, which I __________ (find) on the street. We __________ (go) for long walks every day. Once, when we __________ (walk) back home, a man __________ (approached) me and __________ (try) to mug me. My dog __________ (bite) him in the bottom and the man __________ (start) running away. As he __________ (run), my dog __________ (bark) at him.
7. Jenny and Ken __________ (meet) at a party in 2007. At that time Ken __________ (have) a girlfriend, but Jenny __________ (have/never) a boyfriend before. It __________ (be) love at first sight. When Ken __________ (see) Jenny, he __________ (ask) her to dance with him. As they __________ (dance), Ken’s girlfriend __________ (come) to the party. She __________ (start) shouting at Ken and __________ (remind) him that he __________ (promise) to never leave her for another girl.
8. Randy (drive) his new Porsche to visit his parents. He (buy) the car only two days earlier. I (be) late at night and it (rain) earlier, so the road (be) slippery. However, he (want) to get to his destination as soon as possible, so he (drive) very fast. Suddenly, when he (go) through a forest, something (jump) on the road. In order not to hit it, Randy (step) on the breaks. He (lose) control of the car and (hit) a tree.
2 года назад
Предмет: Русский язык, автор: lyblyjannu
какое из существительное склоняется как прилагательное 1)прибой 2)портной 3)левкой 4)покой 5)герой
2 года назад
Предмет: Русский язык, автор: ЛизаSmile11
Морфологический разбор слова :оконной 5 класс
2 года назад
Предмет: Русский язык, автор: надя687
Выполни морфологический разбор имен существительных.Плывет туман над речкой.Напечатать в газете.В полночной тишине. ​
8 лет назад
Предмет: Биология, автор: Azakrut55
помогите пж 10 баллов отдам ​
8 лет назад