+77 The angles of a quadrilateral are $x$, $5x + 15^\circ $, $3x - 25^\circ$, and $4x - 20^\circ $. Find the measure of the largest angle of the quadrilateral.
+9481 The sum of the angles in a quadrilateral = 360° So.....
x + 5x + 15 + 3x - 25 + 4x - 20 = 360
Combine like terms.
13x - 30 = 360
Add 30 to both sides of the equation.
13x = 390
Divide both sides of the equation by 13 .
x = 30
Since x is positive, the largest angle must be 5x + 15 .
( It has the largest coefficient of x and all the others either add nothing or subtract something. )
And..... if x = 30, 5x + 15 = 5(30) + 15 = 165°
+9481 The sum of the angles in a quadrilateral = 360° So.....
x + 5x + 15 + 3x - 25 + 4x - 20 = 360
Combine like terms.
13x - 30 = 360
Add 30 to both sides of the equation.
13x = 390
Divide both sides of the equation by 13 .
x = 30
Since x is positive, the largest angle must be 5x + 15 .
( It has the largest coefficient of x and all the others either add nothing or subtract something. )
And..... if x = 30, 5x + 15 = 5(30) + 15 = 165°
