Answer :
Answer:
- x = 12
----------------------------------------------
According to the diagram, angle BCD is exterior angle and angles BAC & ABC are remote interior angles of the triangle ABC.
As we know, the exterior angle is the sum of remote interior angles.
Set this as equation and solve for x
- m∠BCD = m∠BAC + m∠ABC
- 6x + 2 = 3x + 15 + 2x - 1
- 6x + 2 = 5x + 14
- 6x - 5x = 14 - 2
- x = 12
Answer:
x = 12
Step-by-step explanation:
Exterior Angle Theorem
The interior angles of a triangle sum to 180°. Angles on a straight line sum to 180°. Therefore, the exterior angle of a triangle is equal to the sum of the two non-adjacent interior angles of the triangle.
Given angles:
- [tex]\textsf{Exterior angle}: \quad m \angle BCD = 6x+2[/tex]
- [tex]\textsf{Non-adjacent interior angle}: \quad m \angle BAC= 3x+15[/tex]
- [tex]\textsf{Non-adjacent interior angle}: \quad m \angle ABC= 2x-1[/tex]
Apply the exterior angle theorem and solve for x:
[tex]\implies m \angle BCD=m \angle BAC+m \angle ABC[/tex]
[tex]\implies 6x+2=3x+15+2x-1[/tex]
[tex]\implies 6x+2=3x+2x+15-1[/tex]
[tex]\implies 6x+2=5x+14[/tex]
[tex]\implies 6x+2-5x=5x+14-5x[/tex]
[tex]\implies x+2=14[/tex]
[tex]\implies x+2-2=14-2[/tex]
[tex]\implies x=12[/tex]