In the rectangular trapezoid oabc, CB / / OA, CB = 10, OC = = 10, OAB = 45 °. Find the coordinates of a, B, C

Let 0 be the origin, OA be the x-axis, OC be the y-axis, make BD ⊥ OA, intersect OA at point D, because OC = 10, CB = 10, so C (0,10), B (10,10) because the angle OAB = 45 ° BD = OC = 10, so ad = cos45 degrees * BD = 1 / 2 * 10 = 5, so od = od + Da = 10 + 5 = 15, so a (0,15)

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