A 70 degree angle is located in the first quadrant of the Cartesian coordinate system.
To understand why, we can look at how angles are measured in standard position. In standard position, an angle of 0 degrees starts along the positive x-axis. As we rotate counterclockwise, we measure the angle in degrees. The first quadrant is defined as the area where both the x and y coordinates are positive, which ranges from 0 to 90 degrees.
Since 70 degrees falls within this range, it clearly lies in the first quadrant. Angles greater than 90 degrees but less than 180 degrees would be found in the second quadrant, while angles from 180 degrees to 270 degrees would be in the third quadrant, and angles from 270 degrees to 360 degrees would be in the fourth quadrant.