Answer:
50°
Explanation:
The total measurement of the sum of the interior angles is 360.
It is given that two of the angles has a measurement of 110. The third angle has a measurement of 90. Let the unknown measurement angle = x. Set the equation:
110 + 110 + 90 + x = 360
Combine like terms:
(110 + 110 + 90) + x = 360
310 + x = 360
Isolate the variable, x. Note the equal sign, what you do to one side, you do to the other. Subtract 310 from both sides:
310 (-310) + x = 360 (-310)
x = 360 - 310
x = 50
50° is the measurement of the remaining angle.