The floor of a gazebo is in the shape of a heptagon. Four of the interior angles measure 135 degrees. The other interior angles have equal measures.

Find their measures

In geometry, you must know that any heptagon, whether regular or not, the sum of all its interior angles is 900°. Having 7 sides, there are also 7 interior angles. Let's write down the algebraic equation using x as the unknown angle of the other interior angles.

900 = 135 (4) + 3x

Solving for x,

x = 120°