![](data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 72 71" width="72"></svg>)
In △ ABC, ab = 6, AC = 4, BC = 8, ad is perpendicular to BC, find the area s
Using the Pythagorean theorem of the second day of junior high school, instead of using Helen's formula, we can get: BD & sup2; - (8-bd) & sup2; = 20, BD = 21 / 4, AD & sup2; + (21,...) from △ abd: AD & sup2; + BD & sup2; = 16 (2) (1) - (2)
In △ ABC, if CD = 3, ab = 6, BC + AC = 8, then the area of △ ABC is______ ．
In △ ABC, CD is the middle line of AB side, and \\\\\\\\\\\\\\\\\\\\\\\\\\\\figure, in \\\\\\\\\\\\\\\\\\\\\\\\\\\282 =7．
In △ ABC, ab = AC, BC = 8, if the area of △ ABC is 8, then AB = AC, BC = 8=
Because AB = AC, the triangle is isosceles triangle. Make a vertical line from point a to BC side and intersect BC at point O. then Bo = Co. because △ area is 8, so Ao = 2 is in right triangle abo. Because Ao = 2, Bo = 2 / 1BC = 4, so AB ^ 2 = Ao ^ 2 + Bo ^ 2. So AB = 2 times root 5
In the known △ ABC, ∠ B = 45 °, ab = 8, AC = 6, calculate the area of △ ABC
∠B=45°,AB=8,AC=6,
The height on BC is 8 / √ 2 = 4 √ 2
Because 6 ^ 2 = 36 > (4 √ 2) ^ 2 6 ^ 2 - (4 √ 2) ^ 2 = 4, the square root is + / - 2
So there are two possibilities: BC = 4 √ 2 + 2 or 4 √ 2-2
Then s △ ABC = 4 √ 2x ((4 √ 2 - 2) / 2 or 4 √ 2x ((4 √ 2 + 2) / 2
RELATED INFORMATIONS
- 1. In known triangle ABC, ab = 5, BC = 6, AC = 7, find the value of tanb and Tanc
- 2. In △ ABC, ab = AC = 10, BC = 16, then CoSb = (), tanb = ()
- 3. In the isosceles 3-angle ABC, ab = AC, if AB = 2BC, find tanb
- 4. In triangle ABC, AB + AC + BC = 1.5 * radical 2, AB * AB + AC * AC + BC * BC = 1.5?
- 5. A triangle ABC, ab = 5, BC = root 5, BC = double root 5. What shape is it
- 6. In the triangle ABC, if (AB) ^ 2 + (AB) * (BC) = 0, then the shape of the triangle is () is a vector Explain
- 7. The three sides a, B and C of △ ABC satisfy that the square of a + the square of B + the square of C = AB + BC + ca
- 8. As shown in the figure, it is a plane figure inlaid by 12 equilateral triangles with equal sides, so the parallelograms in the figure are common______ One
- 9. The visual graph is a plane figure of diamond, The visual graph of a graph is a diamond. Why is the original graph~
- 10. The length of the first square is 1cm more than twice the length of the second side, and the difference of their circumference is 24cm. Find the area of two squares {equation} The distance between the two places is 900m. Xiaohong and Xiaomei set out at the same place at the same time. Xiaohong every minute is 80m. Xiaomei every minute is 100m. When Xiaomei arrived at the destination, she immediately went back along the original road to meet Xiaohong. How many hours did it take them
- 11. In △ ABC, if B = 60 degrees, ab = 2, AC = 2 √ 3, then the area of △ ABC is ?
- 12. In △ ABC, ab = 1, AC = radical 2, angle B = 45 °, find the length of BC and the area of △ ABC
- 13. In △ ABC, ab = AC = 13, BC = 10, then the area of △ ABC is () A. 30B. 60C. 65D. 120
- 14. As shown in the figure, in the triangle ABC, ab = 13, BC = 14, AC = 15, find the length of the high ad on the side of BC
- 15. Given △ ABC and point O, draw the figure after △ ABC rotates 180 ° around point o Don't say that O is the one in the middle, O is outside
- 16. In the isosceles triangle ABC, the angle c = 90 ° and BC = 3cm, if the center point O of AC is taken as the rotation center Rotate the triangle 180 ° and point B falls at B1. How many centimeters has point B changed from the original position of point B1? How do you calculate that
- 17. Let AC = B, BC = a, ab = C, CD = h in RT △ ABC, let AC = B, BC = a, ab = C, CD = H It is known that: in RT △ ABC, ∠ ACB = 90 ° CD ⊥ AB is at point D, let AC = B, BC = a, ab = C, CD = H Proof: a triangle with a + B, h, C + h sides is a right triangle
- 18. If AB = 5 √ 2, find AC and BC
- 19. In known triangle ABC, angle a is 10 degrees less than 2 angle B, and angle B is 30 degrees less than 2 angle C
- 20. In RT △ ABC, ∠ C = 90 °, a = 45 ° is known, AC: BC: ab