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МатематикаВопрос:
3) In an isosceles triangle, one of the base angles is 80°. Find the vertex angle.
Ответ:
Решение:
В равнобедренном треугольнике углы при основании равны. Следовательно, оба известных угла равны 80°. Сумма углов треугольника равна 180°.
- Найдем сумму углов при основании: 80° + 80° = 160°.
- Вычтем эту сумму из 180°, чтобы найти угол при вершине: 180° - 160° = 20°.
Ответ: 20°
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- 7) In the figure ABCD, AB is parallel to CD, and AD is parallel to BC. The angle at vertex A is 137°, and the angle at vertex D is 0. This is likely a typo for a quadrilateral ABCD, where AB is parallel to CD and AD is parallel to BC, which makes it a parallelogram. In a parallelogram, opposite angles are equal and consecutive angles sum to 180°. If angle A is 137°, then angle C is also 137°. Angles B and D would be 180° - 137° = 43°. The notation '0' for angle D is incorrect. Assuming it's a parallelogram with ∠A = 137°.
