As shown in the figure, in the quadrilateral ABCD, ∠ a = 60 °, B = ∠ d = 90 °, BC = 2, CD = 3, find the length of ab

As shown in the figure, in the quadrilateral ABCD, ∠ a = 60 °, B = ∠ d = 90 °, BC = 2, CD = 3, find the length of ab

As shown in the following figure: extend the intersection of AD and BC at point E, because ∠ a = 60 °, ∫ e = 90 ° - 60 ° = 30 °. ∫ CD = 3, ∫ CE = 3 × 2 = 6, then be = 2 + 6 = 8. ∫ AB = 8 × Tan 30 ° = 8 × 33 = 833

Given a (- 3,0), B (3,0), C (- 2,2), if point D is on the Y-axis and the area of the quadrilateral formed by points a, B, C, D is 15, the coordinates of point D are obtained

Let the distance between point D and X-axis be h, ∵ a (- 3,0), B (3,0), ∵ AB = 3 - (- 3) = 6. ① as shown in Figure 1, when point D is on the y-axis coordinate axis, cross point C as CE ⊥ X axis, s quadrilateral abdc = 12 × [- 2 - (- 3)] × 2 + 12 × (2 + H) × 2 + 12 × 3H = 15, H = 245, then the coordinate of point D is (0245). ② as shown in Figure 2, when point D is on the negative half axis of y-axis, s quadrilateral acbd = s △ ABC + s △ abd = 12 × 6 × 2 + 1 2 × 6h = 15, the solution is h = 3. At this time, the coordinates of point D are (0, - 3). To sum up, the coordinates of point D are (0245) or (0, - 3)

If ABCD are mutually unequal rational numbers and | a-c | = | B-C | = | D-B | = 1, then | A-D ||=

-1,1

In trapezoidal ABCD, if ad is parallel to BC, the value of ∠ A: B: C: D may be a.3:5:6:4 b.3:4:5:6 c.4:5:6:3 d.6:5:4:3 D
In trapezoidal ABCD, if ad is parallel to BC, the value of ∠ A: B: C: D may be a.3:5:6:4 b.3:4:5:6 c.4:5:6:3 d.6:5:4:3 D

Because ad is parallel to BC, the value of angle a plus angle B is equal to the value of angle C plus angle D. therefore, according to the proportion, we can see whether the sum of the first two numbers is equal to the sum of the last two numbers. The answer is C. because 4 + 5 = 6 + 3

A [negative 4,3] B [2,5] C [6,3] d [negative 3,0] four points, if the four points of ABCD are connected in sequence, try to judge the shape of the four shape ABCD?

1 find out the four included angles 2 judge the shape according to the relationship between the included angles

In the inscribed quadrilateral ABCD, ∠ A: ∠ B: ∠ C: ∠ d = 3:4:5:6, then ∠ C =?

If the sum of the internal angles of the quadrilateral ABCD is 360 °, then ∠ C = 360 ° / (3 + 4 + 5 + 6) × 5 = 100 °

In rectangular ABCD, if a (- 2,3), B (- 2,5), C (0,5), then what is the coordinate of point d

（0,3） ·····

In rectangular ABCD, the coordinates of points a, B and C are (0,0), (5,0), (5,3) respectively, and the coordinates of point D are

0.3

As shown in the figure, the quadrilateral ABCD is rectangular, point C is on the x-axis, point a is on the y-axis, the coordinates of point D are (0,0), and the coordinates of point B are (3,4). The rectangular ABCD folds along the straight line EF, point a falls at G on the edge of BC, e and F are on AD and ab respectively, and the coordinates of point F are (2,4)
(1) Calculate the coordinates of G point;
(2) The analytic expression of EF is obtained;
(3) Is there a point m on the x-axis and the line EF, so that the quadrilateral with m, N, F and G as the vertex is a parallelogram? If so, please write the coordinates of point m directly; if not, please explain the reason

Analysis: (1) according to the folding property, we know that FG = AF = 2, and FG = ab-af = 1, then in RT △ BFG, we use the Pythagorean theorem to find out the length of BG, so as to get the length of CG, so as to get G-point coordinates; (2) from the meaning, we know that △ AEF is a right triangle with 30 degree angle, so we can get e-point coordinates; and f-point coordinates are known, so we can

It is known that the coordinates of three points on the plane are a (2,1), B (3, - 1), C (- 3,0), and the coordinate of point D is ABCD, which becomes a parallelogram

AB (vector) = ob-oa = (3-2, - 1-1) = (1, - 2)
Let D (x, y)
DC (vector) = AB = oc-od = (1, - 2)
=（-3,0）-（x,y）=（1,-2）
∴-3-x=1 0-y=-2
∴x=-2 y=2
Ψ D (- 2.2) is the required value
Ha ha. Is this calculation process? I hope I can understand it~