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数学 中学生

⭕️の部分がわかりません。教えてください🙏

●三角形の合同を利用して面積を求める 台形の土地の面積をはかる方法 図1は、江戸時代の土地の測量 (検地) のようすを 表したものです。 土地になわをはって、 そのなわの長さから、 台形の土地の面積を求めています。 その方法は、 図2を使って、 次のように説明できます。 台形の土地の面積をはかる方法〉 図1の台形の土地を、図2の台形ABCD で表します。 ここで、AD<BC, DAB= ∠ABC=90°とします。 線分ABの中点をE, 線分 DC の中点をFとして, 線分 EF の位置になわをはります。 このとき AD // EF となります。 図1 「徳川幕府県」より 図2 A G D I ・線分AD上に点 G, 線分 BC 上に点Hを, EFGHと なるようにとり, 線分 GH の位置になわをはります。 はった2本のなわの長さをはかり、その積 (EF×GH) が台形の土地の面積になります。 E F B H 読みとりのポイント 問題文の情報を整理する •∠DAB= ∠ABC=90° ・点Eは線分ABの中点 ・点Fは線分DCの中点 . AD // EF ⚫EFIGH ・台形 ABCDの面積 とEF×GHは等しい。 (1) 図2について, ななみさんは次のように考えました。 (ア)~(ウ) にあてはまる記号を書きなさい。 点Fを通り, 線分ABに平行な直線と, ABJI 直線AD, BC との交点をそれぞれ I J とすると, EF × GH は、 長方形 (ア)の面積になります。 三角形(イ)と三角形 (ウ) が同じ面積なので、 EF × GH は台形ABCD の面積に等しくなります。 (1) DFI (ウ) CFJ EFとGHは、長方形ABJIの横の長さと縦の長さになるので EF×GH は, 長方形ABJIの面積になる。 NO 長方形ABJI と台形ABCDとで異なる部分が,△DFIとCFJである。 長方形 ABJI =五角形ABJFD + ADFI 台形 ABCD =五角形ABJFD+ ACFJ (2) (1)の下線部を次のように証明しました。 証明の過程を書きなさい。 仮定から導けることを 整理する ・四角形 AEFIは 長方形だから, EF=AI EFは長方形ABJI の 横の長さ ・EFIGHより, 同位角が等しいから、 AB // GH 四角形 ABHG は 長方形だから. GH=AB GHは長方形ABJIの 縦の長さ また, にはあてはまる合同条件を書きなさい。 ただし,(イ) (ウ) には,(1)と同じ記号があてはまります。 (証明) ACFJにおいて, LIAB=∠ABC=90°, AB//IJ だから, DIF = ∠CJF=90° 対頂角は等しいから, ① ② ③ より [UF-CT <DFI= ∠CFJ 直角三角形で,斜辺と1つの鋭角がそれぞれ等しいから, ADFI= ACFJ したがって, (イ) =△(ウ) 別解 仮定から, 対頂角は等しいから, DF=CF ∠DFI=∠CFJ AI // BCより、平行線の錯角は等しいから、ID=∠CF ① ② ③より, 1組の辺とその両端の角がそれぞれ等しいから, ADFI= ACFJ (2) 直角三角形の合同条件を ...... 3 確かめる 2つの直角三角形は, 次のどちらかが成り立つ とき合同である。 斜辺と1つの鋭角が それぞれ等しい。 ・斜辺と他の1辺が それぞれ等しい。

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英語 中学生

根気強く英文読める方お願いします🙏 この問題の(2)は合っているでしょうか。 違うのなら違う理由も教えてくれるととても嬉しいです😭お願いします

TREK [3] 9分 10 2935 受験 難問 次の英文を読んで、あとの(1)~(3)の問いに答えなさい。('13 神奈川県) Brian is a high school student from America. He joins a *volunteer club at school. Last Sunday he went to a "nursing home with his friends to teach the old people living there about computers. Mr. Doi, one of the old people there, is talking with Brian in a room at the nursing home. sdgoon 5 Mr. Doi: Hello, I am Kazuo Doi. Nice to meet you. Thank you for coming today. Nice to meet you, too. My name is Brian. What can I do for you, Mr. Doi? Brian Mr. Doi: Can you teach me how to send e-mails, Brian? Brian Mr Doi : Brian Of course, I can. Do you want to send an e-mail to anyone? Yes. One of my friends lives in a nursing home in Hokkaido. I have not seen her for a long time, but she sent me a "postcard last summer. She wrote her *e-mail address on the postcard. I want to send her an e-mail to say "Hello," but I don't know how to do it. salad : Don't worry, Mr. Doi. It is not difficult to send an e-mail. Tellsafi Two days later, Brian and his friend Yumi are talking in their classroom. 15 Yumi Brian Yumi Brian : 20 Yumi : Brian, I hear you went to a nursing home last Sunday, right? : Yes. I went there to do *volunteer work with my friends. : That's great. What did you do there? odon of d We taught the old people living there about computers. They were very glad to learn how to use computers. What did you teach them about computers? I taught some old people how to send e-mails. Mr. Doi was one of them and Brian : his English was good. Read this e-mail from him. He sent it to me yesterday. Brian and Yumi are reading the e-mail from Mr. Doi. Hello, Brian, 100 living here enjoy it. I am sending this e-mail with a picture of me *in front of a microphone." Her e-mail was *encouraging to me. Now I have found an important thing to me. It is to try new things. When I find a new thing to try, I will send you an e-mail again. 35 Kazuo Doi After reading the e-mail from Mr. Doi, Yumi and Brian are talking again. Yumi Mr. Doi enjoys *communication by e-mail. Brian Yes. I'm very happy to hear that. Yumi You did a good thing, Brian. 40 Brian Yumi Brian 45 Yumi : Brian Yumi 50 Brian Yumi 55 Brian T Thank you for coming last Sunday. Do you remember my friend who sent me a postcard with her e-mail address? After I sent her an e-mail, she sent me an e-mail back soon. Using e-mail is a lot of fun. In her e-mail she said, "Now I am trying a new thing in my nursing home. I am *in charge of an announcement over the PA system for 10 minutes in the morning. During this time, I read the *newspaper of the day and make some *comments. Many people Yumi Thank you, Yumi. I went to the nursing home to teach the old people there about computers, but I also learned something there. : What is it, Brian? Mr. Doi knew his friend was in charge of an announcement over the PA system, and then he started to think about trying a new thing, too. I know. Mr. Doi says, "encouraging" in his e-mail. Right. When I taught him how to send e-mails, he said, "I have wanted to learn a lot of things. Using e-mail is one of them." I see. You want to say the e-mail from his friend made him more *positive, right? That's right. First, Mr. Doi learned how to send e-mails and wrote an e-mail to his friend. Next, he got an e-mail from his friend and knew his friend was trying a new thing. Now Mr. Doi ( ) to him. Mr. Doi thinks that it is to try new things. We can say it is good to know how our friends are doing. It is wonderful to *communicate with other people, Brian. : I think so, too. Communicating with other people can make people more positive. I learned that from volunteer work in the nursing home. : I hope that Mr. Doi can find a new thing to try. Please tell me when you get an e-mail from him again. (注) volunteer club ボランティアクラブ nursing home 老人ホーム send〜 〜を送る postcard 絵はがき e-mail address 電子メールアドレス (約 685 語) volunteer work ボランティア活動 in charge of an announcement over the PA system 館内放送を担当して comments コメント in front of a microphone マイクの前の communication by e-mail 電子メールによるコミュニケーション communicate with ~ ~とコミュニケーションをとる newspaper encouraging 励みになる positive 前向きな

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