Answer:
Step-by-step explanation:
The sum of the angles in a triangle is 180 degrees. This means that
Angle A + Angle B + Angle C = 180 degrees
Looking at the triangle,
Angle A = (15x + 10) degrees
Angle B = (15x - 10) degrees
Angle C = (3x + 15) degrees
Therefore,
15x + 10 + 15x - 10 + 3x + 15 = 180
15x + 15x + 3x + 10 - 10 + 15 = 180
33x + 15 = 180
Subtracting 15 from the left hand side and the right hand side of the equation, it becomes
33x + 15 - 15 = 180 - 15
33x = 165
Dividing the left hand side and the right hand side of the equation by 33, it becomes
33x/33 = 165/33
x = 5
Angle A = 15 × 5 + 10 = 85 degrees
