Subtract the sum of the two angles from 180 degrees. The sum of all the angles of a triangle always equals 180 degrees. Write down the difference you found when subtracting the sum of the two angles from 180 degrees. This is the value of X.
Answer:

Step-by-step explanation:
move the decimal so there is one non-zero digit to the left of the decimal point. the number of decimal places you move will be the exponent on the 10. if the decimal is being moved to the right, the exponent will be negative. if the decimal is being moved to the left, the exponent will be positive.
Let x be the angle. The complement is 3x + 10. The sum of two complementary angles is 90. So,
x + 3x + 10 = 90
4x + 10 = 90
4x = 80
x = 20
Plug x into the complement
3(20) + 10 = 70
The angle is 20 degrees and the complement is 70 degrees