you add the three other angles and subtract that from 360
a quadrangle with only one right angle
how do you draw a quadrangle that has at least 1 right angle.
180 minus two known angle = missing angle. Use Pythagoras' theorem to find its missing side.
There is no specific name for such a quadrangle.
In general, you will need to use a protractor and measure them.
I'm guessing a right-angled quadrangle.
Measure the two sides adjacent to the angle and the diagonal at the far ends of these sides. Then use the cosine rule to calculate the angle.
If you are trying to find the missing angle of a triangle you do 180 degrees minus your two other angles. However if you are trying to find the missing angle of a quadrilaterals you do the same thing but with 360 degrees.
360
If the question is about only one right angle, then the answer is a kite, arrowhead or a miscellaneous quadrangle which has no specific name.
Subtract the two known angles from 180 degrees will give you the missing angle
the missing angle is 93 degrees. you find that out by adding 53 and 34 and then subtracting them from 180. :)