Bài tập cuối chương 3
<span data-v-a7c68f28="">Hướng dẫn giải Bài 3.36 (Trang 59 SGK Toán 7, Bộ Kết nối tri thức, Tập 1)</span>
<p><strong>B&agrave;i 3.36 (Trang 59 SGK To&aacute;n lớp 7 - Bộ Kết nối tri thức với cuộc sống):</strong></p> <p>Cho H&igrave;nh 3.52, biết <math xmlns="http://www.w3.org/1998/Math/MathML"><mover><mrow><mi>x</mi><mi>O</mi><mi>y</mi></mrow><mo>^</mo></mover><mo>=</mo><mn>120</mn><mo>&#176;</mo><mo>,</mo><mo>&#160;</mo><mover><mrow><mi>y</mi><mi>O</mi><mi>z</mi></mrow><mo>^</mo></mover><mo>=</mo><mn>110</mn><mo>&#176;</mo></math>. T&iacute;nh số đo g&oacute;c <math xmlns="http://www.w3.org/1998/Math/MathML"><mover><mrow><mi>z</mi><mi>O</mi><mi>x</mi></mrow><mo>^</mo></mover></math>.</p> <p>(Gợi &yacute;: Kẻ th&ecirc;m tia đối của tia Oy).</p> <p><img class="wscnph" style="max-width: 100%;" src="https://static.colearn.vn:8413/v1.0/upload/library/30052022/bai-3-36-trand-59-toan-lop-7-tap-1-1-61Kefn.png" /></p> <p><em><strong>Hướng dẫn giải:</strong></em></p> <p><img class="wscnph" style="max-width: 100%;" src="https://static.colearn.vn:8413/v1.0/upload/library/30052022/bai-3-36-trand-59-toan-lop-7-tap-1-2-Gv1pAY.png" width="330" height="306" /></p> <p>Kẻ Ot l&agrave; tia đối của tia Oy.</p> <p>Do Ot l&agrave; tia đối của Oy n&ecirc;n&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mover><mrow><mi>t</mi><mi>O</mi><mi>y</mi></mrow><mo>^</mo></mover><mo>=</mo><mn>180</mn><mo>&#176;</mo></math></p> <p>hay&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mover><mrow><mi>y</mi><mi>O</mi><mi>x</mi></mrow><mo>^</mo></mover><mo>&#160;</mo><mo>+</mo><mo>&#160;</mo><mover><mrow><mi>z</mi><mi>O</mi><mi>t</mi></mrow><mo>^</mo></mover><mo>&#160;</mo><mo>=</mo><mn>180</mn><mo>&#176;</mo></math></p> <p>Do đ&oacute;&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mover><mrow><mi>z</mi><mi>O</mi><mi>t</mi></mrow><mo>^</mo></mover><mo>&#160;</mo><mo>=</mo><mn>180</mn><mo>&#176;</mo><mo>-</mo><mover><mrow><mi>y</mi><mi>O</mi><mi>z</mi></mrow><mo>^</mo></mover><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mn>180</mn><mo>&#176;</mo><mo>-</mo><mn>110</mn><mo>&#176;</mo><mo>&#160;</mo><mo>=</mo><mn>70</mn><mo>&#176;</mo></math></p> <p>C&oacute; <math xmlns="http://www.w3.org/1998/Math/MathML"><mover><mrow><mi>t</mi><mi>O</mi><mi>y</mi></mrow><mo>^</mo></mover><mo>=</mo><mn>180</mn><mo>&#176;</mo></math> hay&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mover><mrow><mi>y</mi><mi>O</mi><mi>x</mi></mrow><mo>^</mo></mover><mo>+</mo><mover><mrow><mi>x</mi><mi>O</mi><mi>t</mi></mrow><mo>^</mo></mover><mo>=</mo><mn>180</mn><mo>&#176;</mo></math></p> <p>Do đ&oacute;&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mover><mrow><mi>x</mi><mi>O</mi><mi>t</mi></mrow><mo>^</mo></mover><mo>=</mo><mn>180</mn><mo>&#176;</mo><mo>-</mo><mover><mrow><mi>y</mi><mi>O</mi><mi>x</mi></mrow><mo>^</mo></mover><mo>=</mo><mn>180</mn><mo>&#176;</mo><mo>-</mo><mn>120</mn><mo>&#176;</mo><mo>=</mo><mn>60</mn><mo>&#176;</mo></math></p> <p>Do đ&oacute;&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mover><mrow><mi>x</mi><mi>O</mi><mi>z</mi></mrow><mo>^</mo></mover><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mover><mrow><mi>z</mi><mi>O</mi><mi>t</mi></mrow><mo>^</mo></mover><mo>+</mo><mover><mrow><mi>x</mi><mi>O</mi><mi>t</mi></mrow><mo>^</mo></mover><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mn>70</mn><mo>&#176;</mo><mo>+</mo><mn>60</mn><mo>&#176;</mo><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mn>130</mn><mo>&#176;</mo></math></p> <p>Vậy&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mover><mrow><mi>x</mi><mi>O</mi><mi>z</mi></mrow><mo>^</mo></mover><mo>=</mo><mn>130</mn><mo>&#176;</mo></math></p>
Xem lời giải bài tập khác cùng bài