If three line segments of length A-2, a + 5 and a + 2 are connected in turn to get a triangle, then the value range of a is () A. A ＞ - 1B. A ＞ 2C. A ＞ 5D

If three line segments of length A-2, a + 5 and a + 2 are connected in turn to get a triangle, then the value range of a is () A. A ＞ - 1B. A ＞ 2C. A ＞ 5D

Because - 2 ＜ 2 ＜ 5, so A-2 ＜ a + 2 ＜ a + 5, so A-2 + A + 2 ＞ a + 5 can be obtained from the triangle trilateral relation, and the solution set of the inequality is a ＞ 5

If the three line segments of length 4, 6 and X can form a triangle, then the value range of X is

If the three line segments of length 4, 6 and X can form a triangle, then the value range of X is 2 < x < 10

If the length of the two median lines of △ ABC is 6 and 3 respectively, the maximum area of △ ABC is 0______ ．

As shown in the figure, if the middle line ad = 6, be = 3, then AF = 4, BF = 2, EF = 1, let ∠ AFB = α, ｜ s △ ABC = 2S △ Abe = 2 (s △ ABF + s △ AEF) = 2 [12af · BF · sin α + 12af · EF · sin (π - α)] = 8sin α + 4sin α = 12sin α ≤ 12, then when α = 90 °, that is, when the two middle lines are vertical, the maximum value of s △ ABC is 12

The triangle is divided into six parts by three central lines, and the relationship between its area and size is as follows

Because the proportion of the central line segment is 2:1, the area is equal

Know the length of the three sides of a triangle, how to find the area of the triangle
For example, all three sides are 1.5cm triangles. The faster the better,

The area of equilateral triangle s = √ 3 / 4 * the square of side length

How to lay the floor of 5m long and 3M wide with two triangular floors with right angle sides of 30cm and 10cm respectively? How to lay the floor of 3M wide and 5m long?

As shown in the figure: ∵ 30cm = 0.3m, 10cm = 0.1M, ∵ at least the number of triangular floor blocks required is: 15 (0.3 × 0.1) = 500 (blocks), a: at least 500 triangular floor blocks are required

In triangle ABC, if a = 3M, B = 4m + 1, C = 2-5M, and ∠ C = 90 °, what is the value of M?

From C = 90, a + B = C 9m2 + 16m2 + 1 + 8m = 4 + 25m2-20m, M = 3 / 28

The bottom edge of a triangle is 30cm long and 20cm high. If you draw it on a plan, its side length is 10cm. How much cm should you draw?

y6330579,
Gao should draw:
10 △ 30 × 20 = 20 / 3 (CM)

In △ ABC, AC = 5 and midline ad = 7, then the value range of AB side is______ ．

Extend ad to e to make de = ad, connect be, ∵ D is the midpoint of BC, ∵ CD = BD

Given that ad is the middle line of triangle ABC, find the size of 2ad and ab + AC

Extend ad to e, make de = ad, connect EB, EC
Then: ABEC is a parallelogram
EC=AB
In triangular AEC,
AC+EC>AE
AC+AB>2AD