#### Answer

35 degrees, 70 degrees

#### Work Step by Step

Let the first unknown angle be $x$ degrees.
Since the second angle is twice the first, we let the second unknown angle be $2x$ degrees.
Since the sum of the three angles of a triangle is always $180$ degrees, we write the following equation and solve:
$x+2x+75=180$
$3x+75=180$
$3x=180-75$
$3x=105$
$x=\frac{105}{3}=35$
Therefore, the first unknown angle is $35$ degrees while the second unknown angle is $35(2)=70$ degrees.