Question

Three interior angles of a quadrilateral measure 55°, 117°, and 120°. What is the measure of the fourth interior angle? 68° 78° 88° 98°

Answer 1

angles are 55,117,120 so the total measure of quadrilateral 360 so the last angle is 68

Answer 2

Answer:

the answer is A) 68 degrees

Step-by-step explanation:

we first needs to know how many triangles are in the polygon:

which is (n-2) triangles, where n equals the number of sides. and for this shape it is 4. so 4-2=2 triangles.

Next, we know that the sum of all angles in one triangle is 180 degrees. when there's two, it equals 360.

The final step is just to subtract the three angles we already know from 360, 360-55-117-120=68

and that is your answer.