In △ ABC, ∠ C = 90 °, ab = 41, the perimeter of △ ABC is 90, try to find the area of △ ABC,

In △ ABC, ∠ C = 90 °, ab = 41, the perimeter of △ ABC is 90, try to find the area of △ ABC,

Let AC = x, BC = y
Then: x + y = 90-41 (1)
x²+y²=41²（2）
(1) Square of both sides: X & # 178; + 2XY + Y & # 178; = 49 & # 178; (3)
(3) (2) get: 2XY = 720
1/2xy=180
So area = 1 / 2XY = 180

Let M2 + M-1 = 0, then m3 + 2M2 + 2010=______ ．

If ∵ M2 + M-1 = 0, ① ∵ ① × m, m3 + m2-m = 0, ② ∵ ① + ②, m3 + 2m2-1 = 0, namely m3 + 2M2 = 1, then m3 + 2M2 + 2010 = 1 + 2010 = 2011

Given 2A ^ 2 + A-2 = 3, find the value of 4A ^ 2 + 2A + 2010

2a^2+a = 5
2*(2a^2+a) = 10
4a^2+2a = 10
4a^2+2a+2010 = 2020

Given a ^ 2 + A-1 = 0, find the value of a ^ 3 + 2A ^ 2-2009

The traditional form of love
∵a^2+a-1=0
∴a^2+a=1
a^3+2a^2-2009
=(a^3+a^2)+a^2-2009
=a(a^2+a)+a^2-2009
=a+a^2-2009
=(a+a^2)-2009
=1-2009
=-2008

If a ^ 2 + a = - 1, then the value of a ^ 3 + 2A ^ 2 + 2A + 3 is ()

a^2+a+1=0,
a^3+2a^2+2a+3
=a³+a²+a+a²+a+1+2
=a(a²+a+1)+(a²+a+1)+2
=2

In triangle ABC, angle a-angle B = 30 degrees, angle B-angle C = 36 degrees, find angle A

Angle a-angle C = 76 is obtained from angle a-angle B = 30 degrees and angle B-angle C = 36 degrees

In △ ABC, given that angle A-B = 30 degrees, angle a-c = 36 degrees, what triangle is △ ABC

Let angle a be x degrees, then angle B be X-30 degrees, and angle c be x-36 degrees. According to the equation x + X-30 + x-36 = 180, we can calculate that x is 82 degrees, so it's an acute triangle, right? I'm blind,

In △ ABC, ∠ a = 68 ° 36 ′, ∠ B = 57 ° 24 ′, then ∠ C=

54 degrees

If there are three numbers a, B and C, a × B = 24, a × C = 36 and B × C = 54, then a + B + C=______ ．

Because (a × b) × (a × C) / (B × C) = 24 × 36 / 54 = 16, that is, A2 = 16, so a = 4, B = 24 / a = 6, C = 36 / a = 9, a + B + C = 4 + 6 + 9 = 19

In the triangle ABC, the angle ACB is equal to 78 degrees, the angle a is equal to 32 degrees, and the point de folds the triangle along the straight line de on AC ab
To get triangle a 'de, please explore the angle after folding according to the following requirements

As shown in Figure 1, △ a'de is inside the quadrilateral BCDE. Find the sum of ∠ 1 + 2; 3. As shown in Figure 3, △ ade is folded up along the straight line De, trying to explore the quantitative relationship of ∠ 1, ∠ 2, ∠ a (1)