The center of gravity in the triangle ABC is g, GA = 2 times the root 3, GB = 2 times the root 2, GC = 2, and the area of the triangle GBC is calculated

The center of gravity in the triangle ABC is g, GA = 2 times the root 3, GB = 2 times the root 2, GC = 2, and the area of the triangle GBC is calculated

Let BG intersection AC be D, extend GD to de, let de = Gd, connect AE. Because the center of gravity of triangle ABC is g, and GB = 2 times root 2, then GD = root 2 = De, so Ge = 2 times root 2, and triangle AED congruent GDC, so AE = GC = 2, s triangle AED = s triangle GDC, so Ag ^ 2 = Ge ^ 2 + AE ^ 2, so angle AEG = 90, so triangle a

Δ ABC, the center of gravity is g, if the vector GA of times a + the vector GB of times B + the root of three thirds and the vector GC of times C = the zero vector, then ∠ a=_______

G is the center of gravity, GA + GB + GC = 0, (1),
Given the formula - (1) * C / √ 3, we get
（a-c/√3）GA+(b-c/√3）GB=0,
GA, GB are not collinear,
∴a-c/√3=b-c/√3=0,
∴a=b=c/√3,
From the cosine theorem, cosa = - 1 / 2,
∴A=120°.

As shown in Figure 3, in the isosceles triangle ABC, the angle B = angle c = 30 ° is used to calculate the probability of the following events
Make a ray AP in the interior of angle ABC and intersect BC with P to make BP smaller than ab

The starting point of angle P is when ∠ BAP = 5 / 12 π,
The range of ∠ PAB in the population is (0,2 π / 3)
According to the geometric model
P(A)=75/120=15/24=5/8

An isosceles triangle ABC (as shown in the figure) has a circumference of 28cm. The heights of its two sides are 5cm (AD) and 4cm (be). What is the area of this isosceles triangle in square centimeter?

Because the height of the two sides of the isosceles triangle ABC is 5cm (AD) and 4cm (be), so AB: AC: BC = 5:5:4, so BC = 28 × 45 + 5 + 4 = 8 (CM). 8 × 5 △ 2 = 20 (cm 2). A: the area of the isosceles triangle is 20cm 2