To find the missing angle in a quadrilateral, we need to use the fact that the sum of the angles in a quadrilateral is always 360°.
Let's denote the missing angle as x.
Given that the three known angles are 59°, 129°, and 78°, we can write an equation for the sum of all four angles:
59° + 129° + 78° + x = 360°
Simplifying the equation:
266° + x = 360°
Subtracting 266° from both sides of the equation:
x = 360° - 266°
x = 94°
Therefore, the missing angle measures 94°.
A quadrilateral has 3 angles measuring 59°, 129° and 78°. What does the missing angle measure?
1 answer