Step-by-step explanation:
Let the angle near point A be
.
Let the angle near point B be
.
Let the angle near point C be
.
Let the external angle near point A be
.
Let the external angle near point B be
.
Let the external angle near point C be
.
According to exterior angle property,exterior angle of an angle is the sum of other two angles.
So,

According to angle sum property,the sum of angles in the triangle add to 

Answer:
okay
Step-by-step explanation:
Answer:
26
Step-by-step explanation:
5 × 4 = 20 (rectangle)
8-5 = 3 (triangle)
3×4÷2 = 6
20+6 = 26
Answer:
x = 2 ±i
Step-by-step explanation:
x^2 = 4x-5
Subtract 4x from each side
x^2 - 4x = 4x-5 -4x
x^2 - 4x= -5
Complete the square
Take the coefficient of the x term, divide by 2 and square it
-4/2 =2 2^2 =4
Add 4 to each side
x^2 -4x+4 = -5 +4
The left side is (x-coefficient of the x term/2)^2
(x-2)^2 = -1
Take the square root of each side
sqrt((x-2)^2) = sqrt(-1)
x-2 = ±i
Add 2 to each side
x-2+2 = 2 ±i
x = 2 ±i