Final answer:
The size of one of the equal angles in a heptagon with four known angles can be found by subtracting the sum of the known angles from the total sum of angles and dividing by the number of remaining angles.
Step-by-step explanation:
The sum of the angles in a heptagon is equal to (n-2) * 180 degrees, where n is the number of angles in the polygon. In this case, since a heptagon has 7 angles, the sum of the angles is (7-2) * 180 = 900 degrees.
Given that four angles are already known, we can find the sum of these angles by adding them together: 118 + 105 + 140 + 135 = 498 degrees.
To find the sum of the remaining angles, we subtract the known sum from the total sum: 900 - 498 = 402 degrees.
Since the remaining angles are equal, we divide the sum by the number of angles: 402 / 3 = 134 degrees.