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As shown in the figure, the length of the rectangle is 6cm, the width is 4cm, and the area of the shaded triangle is 9cm2. Find the length of BD. how to prove the vertical length of be
The one upstairs is right. If you don't understand it, you can do this: set △ BDA and △ BDC. The height with BD as the bottom is x and Y respectively, and get x + y = 4, s △ ABC = s △ BDA + s △ BDC = BD * x? BD * y? 9 BD(x+y)? 9 BD=4.5cm
A rectangle. The width ratio of the upper and lower rectangles divided by line AB is 3:5. The area of the shadow triangle in the figure is 15 square centimeters Find the area of the original rectangle?
First, ask for the area of the following large rectangle: 15 * 2 = 30 (square centimeter), then divide 30 by the width ratio of the following rectangle: 30 / 5 = 6 (centimeter), then multiply 6 cm by the width ratio of the upper rectangle: 6 * 3 = 18 (square centimeter), and then add 18 square centimeter and 30 square centimeter: 18 + 30 = 48 (square centimeter). A: the area of the original rectangle is 48 square centimeter
As shown in the figure, the length of the rectangle is 12cm and the width is 6cm, in which the area of triangle ① is 20cm2. Calculate the area of the shaded part
twelve × 6-20，
=72-20，
=52 (cm2),
A: the area of the shaded part is 52 square centimeters
As shown in the figure, the area of the shaded part in the circle accounts for 1% of the circle area 6, accounting for 1% of the rectangular area 5； The area of the shaded part in the triangle accounts for 1% of the triangle area 9, accounting for 1% of the rectangular area 4. Area ratio of circle, rectangle and triangle () A. 24：20：45 B. 12：10：22 C. 48：40：89 D. 20：28：42
Let the area of the circle be 6S, ∵ the area of the shadow part in the circle accounts for 16 of the area of the circle, ∵ the area of the shadow part in the circle = s, and ∵ the area of the shadow part in the circle accounts for 15 of the rectangular area, ∵ the rectangular area = 5S; The area of the shaded part in the triangle accounts for 14% of the rectangular area, and the area of the shaded part in the triangle = 5s4
As shown in the figure, the length of the rectangle is 12cm and the width is 6cm, in which the area of triangle ① is 20cm2. Calculate the area of the shaded part
twelve × 6-20，
=72-20，
=52 (cm2),
A: the area of the shaded part is 52 square centimeters
As shown in the figure, it is a hexagon composed of 9 equilateral triangles. Now it is known that the side length of the smallest equilateral triangle in the middle is a, so find the perimeter of the hexagon I've seen the process that when the side length of the minimum equilateral triangle is 1, the perimeter of the hexagon is 30; So, in this question, is the perimeter of the hexagon 30A?
Let EF = x, NF = 2x, AP = 2x-a, MC = 2x-2a, then Mn = md-ef = 2x-2a-x = x-2a, and Mn = a, so x-2a = a, x = 3A, perimeter = EF + AF +. = x + 2x + 2x-a + 2x-2a + (2x-2a + x) = 30A
RELATED INFORMATIONS
- 1. As shown in the figure, the side length of the regular triangle ABC is 6. Cut off three corners to get a regular hexagon. Find the side length and area of the regular hexagon
- 2. Cut out a square as large as possible, the largest square, from an isosceles right triangle cardboard with an inclined edge of 18cm long What is the side length of the?
- 3. In the acute triangle ABC, the opposite sides of angles a, B and C are a, B and C respectively, and the root number 3B = 2asinb is known to calculate the size of the angle; If a = 6, find the range of B + C
- 4. In triangular row ABC, a equals 1, C equals 2, and B equals 60 degrees. What is the area of triangular ABC
- 5. It is known that in △ ABC, the side opposite the acute angle B = 7, the radius of the circumscribed circle r = 7 times the root number 3 / 3, and the triangle area s = 10 times the root number 3. Find the length of the other two sides of the triangle
- 6. In △ ABC, a = 60 °, C: B = 8:5, the area of the inscribed circle is 12 π, and the radius of the circumscribed circle of △ ABC is calculated
- 7. If the perimeter of a right triangle is 5cm and the center line on the hypotenuse is 1cm, the area of this right triangle is?
- 8. Given that the perimeter of a right triangle is 30 and the area is 30, find the oblique side length of the triangle
- 9. If the area of the triangle enclosed by the straight line y = 2x + m on the two coordinate axes is equal to m, the value of M is
- 10. The lengths of both sides of the triangle are 8 and 6 respectively. The length of the third side is a real root of the univariate quadratic equation x2-12x + 20 = 0. Find the area of the triangle
- 11. In △ ABC, the opposite sides of angles a, B and C are a, B and C respectively, and meet 2C − B a＝cosB cosA． (I) find the size of angle a; (II) if a = 2 5. Find the maximum value of △ ABC area
- 12. As shown in the figure, in triangle ABC, ab = AC = 20, angle B is equal to 15 degrees, then the area of triangle ABC
- 13. If triangle ABC is all equal to triangle a'b'c ', ab = 24 and triangle a'b'c' area = 180, then the height on the side of AB in triangle ABC is equal to?
- 14. In triangular ABC, the ratio of angle a to angle B to the degree of angle c is 1 to 2 to 3 BC = 4. Calculate the area of triangular ABC
- 15. In triangle ABC, A.B.C is the length of the side opposite angle A.B.C, and S is the area of triangle ABC Know s = a Λ 2 - (B-C) Λ2. Find Tana
- 16. In △ ABC, a, B and C are the opposite sides of ∠ a, ∠ B and ∠ C respectively. If a, B and C form an equal difference sequence, ∠ B = 30 °, the area of △ ABC is 3 2, then B equals () A. 1+ three two B. 1+ three C. 2+ three two D. 2+ three
- 17. : if the area of triangle ABC is s and the three sides are a, B and C, what is the radius of the inscribed circle of the triangle?, : fill in the blanks, : it's probably expressed by a, B, C and s,
- 18. In triangle ABC, cosa = 3 / 5, find the value of COS ^ (A / 2) - sin (B + C)
- 19. In triangle ABC, given sin (a + b) = 0.6, sin (a-b) = 0.2 and ab = 3, find the area of triangle ABC
- 20. In triangle ABC, if a satisfies the root sign 3sina + cosa = 1, ab = 2, BC = 2 and root sign 3, the area of triangle ABC is