Вопрос:
Задание 33. Дан прямоугольник ABCD. Заполните пропуски в таблице.
Ответ:
| № | AB | AD | SABCD | OM | SABO | SAMC |
|---|
| 1 | 6 | 8 | 48 | 5 | 15 | |
| 2 | 10 | 16 | 160 | 8 | 40 | |
| 3 | 8 | | | | 30 | 18 |
| 4 | | 10 | | 4 | | |
| 5 | | 8 | | | | 24 |
| 6 | | | 60 | 3 | | |
| 7 | 7 | | | | 21 | |
| 8 | | | | 2 | | 16 |
Решение:
- SABCD = AB × AD = 6 × 8 = 48
- OM = \(\sqrt{OA^2 - AM^2}\) = \(\sqrt{5^2 - 3^2}\) = 4
- SABO = 1/2 × AB × OM = 1/2 × 6 × 5 = 15
- SAMC = 1/2 × AM × CD = 1/2 × 3 × 8 = 12
- AD = SABCD / AB = 160 / 10 = 16
- OM = \(\sqrt{OA^2 - AM^2}\) = \(\sqrt{10^2 - 6^2}\) = 8
- SABO = 1/2 × AB × OM = 1/2 × 10 × 8 = 40
- SAMC = 1/2 × AM × CD = 1/2 × 6 × 10 = 30
- SABO = 30, AB = 8, OM = 2SABO / AB = 2 × 30 / 8 = 7.5
- AD = 2 × OM = 2 × 7.5 = 15
- SABCD = AB × AD = 8 × 15 = 120
- SAMC = 1/2 × AM × CD = 1/2 × 7.5 × 8 = 30
- OM = 4, AD = 10, AM = AD / 2 = 10 / 2 = 5
- OA = \(\sqrt{OM^2 + AM^2}\) = \(\sqrt{4^2 + 5^2}\) = \(\sqrt{41}\)
- AB = 2 × OA = 2 × \(\sqrt{41}\)
- SABO = 1/2 × AB × OM = 1/2 × 2√41 × 4 = 4√41 ≈ 25.61
- SABCD = AB × AD = 2√41 × 10 = 20√41 ≈ 128.06
- SAMC = 1/2 × AM × CD = 1/2 × 5 × 2√41 = 5√41 ≈ 32.02
- AD = 8, SAMC = 24, AM = 2SAMC / CD = 2 × 24 / AB = 2 × 24 / AB
- OA = OD, => O - центр прямоугольника, => AO = BO = CO = DO
- MC = AM, AM = AD / 2 = 8 / 2 = 4
- AB = CD, => CD = 8, AM = 2SAMC / CD = 2 × 24 / 8 = 6
- AB = \(\sqrt{BC^2 + AC^2}\)
- OM = 1/2 AB, => AB = 2OM = 2 × 3 = 6
- AD = SABCD / AB = 60 / 6 = 10
- AM = AD / 2 = 10 / 2 = 5
- SABO = 1/2 × AB × OM = 1/2 × 6 × 3 = 9
- SAMC = 1/2 × AM × CD = 1/2 × 5 × 6 = 15
- AB = 7, SABO = 21, OM = 2SABO / AB = 2 × 21 / 7 = 6
- AD = 2 × OM = 2 × 6 = 12
- SABCD = AB × AD = 7 × 12 = 84
- AM = AD / 2 = 12 / 2 = 6
- SAMC = 1/2 × AM × CD = 1/2 × 6 × 7 = 21
- OM = 2, SAMC = 16, CD = 2SAMC / AM = 2 × 16 / AM
- AM = MC, AD = 2 × AM, CD = AB
- AD = BC, => AM = AD / 2
- SABO = SAB × OM / 2
- SABCD = AD × AB
- OM = AM2 + AO2, AO = 1/2 × AC, AC = \(\sqrt{AD^2 + DC^2}\)
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