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不久前,我校组织了一次初三数学第二课堂活动,效果较好,今介绍如下: 为便于说明,称等腰直角三角形三角板为“等腰板”,另一块含60°角的三角板为“非等腰板”。且等腰板的斜边长等于非等腰板的长直角边长,设非等腰板的短直角边长为1,则两块三角板各边长如图(1)所示。下面给出用两板拼叠法求出sin15°的值
Not long ago, the school organized a third mathematics second class activity, and the effect was relatively good. Today’s introduction is as follows: For the sake of illustration, the isosceles right triangular board is called “isosceles board”, and another triangular board with 60 degrees is “ Non-isotonic plate”. The length of the hypotenuse of the isosceles plate is equal to the length of the long right side of the non-isoclinic plate, and the length of the short right side of the non-isosceles plate is 1, then the lengths of the sides of the two triangular plates are shown in (1). Given the value of sin15° using the two-plate overlap method below