All the interior angles of a triangle always add up to 180 degrees.
3x + (2x + 20) + (4x - 20) = 180
3x + 2x + 20 + 4x - 20 = 180
3x + 2x + 4x + 20 - 20 = 180
10x = 180
x = 180/10
Therefore, x = 18
Answer:
1
Step-by-step explanation:
4(1)-3=?
4-3=1
A regular n-gon has n lines of symmetry
The angle of rotational symmetry for regular n-gon is 360 / n degrees.
Answer:
-3 <x <-1
Step-by-step explanation:
|x + 2| < 1
There are two solutions, one positive and one negative ( remember to flip the inequality for the negative)
x+2 <1 and x+2 > -1
Subtract 2 from each side
x+2-2 < 1-2 and x+2-2 > -1-2
x < -1 and x >-3
-3 <x <-1
