Question

A quadrilateral has three angles equal to 75°, 75° and 110°. Find its unknown angle.

Answer 1

<1+<2+<3+<4 = 360
75+75+110+<4 = 360
260+<4 = 360
<4 = 360-260
<4 = 100

Answer 2

75+75+110+x. =360
260+x=.360
x= 360-260
x=100