Answer:
A=40°
Step-by-step explanation:
All angles in a triangle add up to 180°, so we take 60 away from 180 because we know that angle.
180-60=120
Next, we add up the number of x,
10x+20x=30x
Third, we need to find out what x is, so we divide 120 by 30, which gives us 4.
x=4
to find out what 10x is (A), we multiply 4 by 10
4×10=40
A=40
