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It is known that the length of the base and the waist of an isosceles triangle are 6 and 5, respectively
S = 6 * 4 / 2 = 12, find out (the square of 5 - the square of 3) = 4 under the high = root sign
The area of isosceles triangle is 12, the height of base is 4, and the waist length is 5
Question: is this proposition true?
S = 1 / 2 × bottom × 4 = 12
Bottom = 6
According to the isosceles triangle, the half of the bottom is 3
According to Pythagorean theorem, because 3 & # 178; + 4 & # 178; = 5 & # 178;
So it's a true proposition
The vertex angle of the isosceles triangle is 150 ° and the waist length is 6cm?
Area of triangle = (1 / 2) AB * sin ∠ C = 1 / 2 * 6 * 6 * sin 150 ° = 9cm2
The area formula of isosceles triangle only knows waist length
Known waist length is 20 centimeters, seek area, get out
The condition is not enough, because there is s = 1 / 2A * asin (c) in the area formula
The area is: S = 1 / 2 * 20 * 20 * sin (60)
If the waist length of an isosceles triangle is 10 and the bottom length is 12, then the height of one waist of the isosceles triangle is equal to
48 / 5, 9.6, the Pythagorean theorem of base height is 10, and then the area conversion h * 10 = 12 * 8 is used to get H = 9.6
The waist length of an isosceles triangle is 10, and the base length is 12. To find the radius of its inscribed circle, we need to do the following
From Pythagorean theorem to find the height of the base is 8
Triangle area = 12 × 8 ÷ 2 = perimeter × R / 2 r = 3
If the length of the lower side of an isosceles triangle is 10, and the median line on the bottom side is 12, then the waist length is?
According to the Pythagorean theorem, the waist length is 13
If the waist length of an isosceles triangle is 10 and the base length is 12, then the height of the base is ()
A. 6B. 7C. 8D. 9
If we make the height on the bottom and let the length of the height be x, then according to the Pythagorean theorem, we get 62 + x2 = 102; the solution is x = 8, so we choose C
The waist length of an isosceles triangle is 10, and the area is 48
Let the bottom edge be X
(x/2)^2+(48*2/x)^2=10^2
x1=12
x2=16
In a math class, the teacher asked the students to cut an isosceles triangle with a waist length of 10 cm on a rectangular cardboard with a length of 18 cm and a width of 16 cm. One vertex of the isosceles triangle should coincide with one vertex of the rectangle. If the other two vertices are on the edge of the rectangle, what is the area of the isosceles triangle ()
A. 50B. 50 or 40C. 50 or 40 or 30d. 50 or 30 or 20
As shown in the figure, the quadrilateral ABCD is rectangular, ad = 18cm, ab = 16cm; this problem can be divided into three cases: ① as shown in the figure (1): △ AEF, AE = AF = 10cm; s △ AEF = 12 · AE · AF = 50cm2; ② as shown in the figure (2): △ AGH, Ag = GH = 10cm; in RT △ bGH, BG = Ab-Ag = 16-10 = 6cm; according to the Pythagorean theorem, there are: BH = 8cm; s △ AGH = 12ag · BH = 12 × 8 × 10 = 40cm2; ③ as shown in the figure (3): △ amn, am = Mn = 10cm In RT △ DMN, MD = ad-am = 18-10 = 8cm; according to Pythagorean theorem, DN = 6cm; s △ amn = 12am · DN = 12 × 10 × 6 = 30cm2
RELATED INFORMATIONS
- 1. Be sure to see a reward. Pick up an isosceles triangle with a waist length of 10cm on a rectangular cardboard with a length of 17cm and a width of 16cm Very important, please answer with conscience! (one vertex of triangle and one vertex of rectangle are required to coincide, and the other two vertices are on the side length of rectangle). Please draw a figure or use words to show the detailed drawing process and find the method of drawing acute angle
- 2. The circumference of an isosceles triangle is 32cm. The length of the waist is 3 times longer than that of the bottom, which is 6cm more than that of the bottom. Find the length of each side
- 3. An isosceles triangle, one side is 30 cm long, the other side is 65 cm long, the triangle circumference is 30 cm
- 4. The circumference of an isosceles triangle is 160cm. The ratio of the waist length to the bottom length is 3:2. What is the waist length and the bottom length of this triangle
- 5. The ratio of the length of a waist to the length of the bottom of an isosceles triangle is 4:3. The circumference of the triangle is 528 cm. How many cm is the length of the bottom
- 6. An isosceles triangle, in which the length of two sides are 5 / 3 decimeter and 4 / 1 decimeter respectively, calculate the perimeter
- 7. It is known that the waist length of an isosceles triangle is 3 / 4 of the length of its base, and the length of one side is 11cm, then its circumference is_____________ .
- 8. If the vertex angle of an isosceles triangle is known to be 40 degrees, then the angle between the height of its waist and the bottom is 40 degrees______ ．
- 9. If the acute angle between the heights of the two waists of an isosceles triangle is 70 degrees, what are the degrees of the three internal angles of an isosceles triangle?
- 10. In ABC, ab = 7, AC = 5, BC = 3, find SINB, CoSb
- 11. The girth of an isosceles triangle is 16cm, the height of its bottom is 4cm
- 12. Let the length of one side of a triangle with an area of 12 square centimeters be a (?) and the height of this side be h (?). (1) find the analytic expression of the function of H with respect to a and the independent variable a Value range; (2) Is the function of H about a an inverse scale function? If so, please state its scale coefficient; (3) If the area of the triangle is changed to a fixed value s (square centimeter), and the rest is unchanged, find the analytic function of H with respect to a Solution
- 13. Draw a triangle with the largest area in a rectangle. The area ratio of the triangle to the rectangle is ()
- 14. Draw the largest triangle in the square. The area of the triangle is () of the area of the parallelogram
- 15. As shown in the figure, the rectangle efgh is connected to △ ABC, the bottom edge of △ ABC AC = B, the height BD = h, and the height eh = X. try to write out the functional relationship between the rectangle area s and X, and find out the value range of X
- 16. As shown in the figure, pdce is rectangular, ABCD is trapezoidal, plane pdce ⊥ plane ABCD, ∠ bad = ∠ ADC = 90 # 186;, ab = ad = # 189; CD = a, PD = √ 2 (1) If M is the midpoint of PA, the MDE of AC ‖ plane is proved; (2) Find the size of the sharp dihedral angle between planar pad and PBC
- 17. On the calculation of Newton's law 1. A truck with a mass of 50000kg runs along a smooth horizontal road at a speed of 0.3m/s, with a rope trailing behind it. If the tension of the rope is 250N, how long does it take to stop the truck? 2. There is a speed limit sign of 30km / h in a certain section. After the driver makes an emergency brake in this section, the inspector measures that the length of the brake trace is 12m. If the dynamic friction coefficient between the tire and the road is 0.6, ask the driver whether he has violated the speed limit specified in this section of the road. (hint: calculate the acceleration when braking from the braking friction, and then calculate the initial speed from the kinematic formula.)
- 18. 2lg(2x-1)=lg(-2x+7)+lg(x+1)
- 19. Simple calculation of 8 * (X-5) = 1
- 20. The simple calculation is 5.7 × 1 + 2.5 △ 47.23 + 14.75-6.87 + 2.77-8