Question

If a quadrilateral has three angles measuring 60° , 45° , and 100°, find the measure of the fourth angle.

Answer 1

A quadrilateral has four sides meaning it will also have four angles that all add up to 360 degrees. Since you already know three of the angles (60, 45 and 100) you just need to add them up and subtract the answer from 360.

60+45+100=205
360-205=155

So the fourth angle is 155 degrees