Supplementary angles are when two angles have a sum of 180°.180°. Typically, these angles lie on a straight line.
Opposite angles of a parallelogram have equal values.
Find the missing supplementary angle, which is equal to the value of xx.
First, we can see from the diagram that the exterior angle 75°75° and the interior angle ∠ADC∠ADC lie on a straight line. Therefore, they are supplementary angles
Since supplementary angles add to 180°,180°, add the angle measures and set their sum to 180°.180°. Then, solve for the value of aa.
∠ADC+75∠ADC+75
==
180180
∠ADC+75∠ADC+75-75−75
==
180180-75−75
Subtract 7575 from both sides
∠ADC∠ADC
==
105°105°
Finally, the angle ∠ADC∠ADC is opposite to angle xx
Since opposite angles on a parallelogram are equal, ∠x=105°∠x=105°
An Isosceles Triangle has two congruent sides (the two sides with dashes) and the two base angles are equal.
Supplementary angles are when two angles have a sum of 180°.180°. Typically, these angles lie on a straight line.
The sum of the interior angles in a quadrilateral is 360°360°
To solve for ∠BED∠BED, first find ∠EBC∠EBC. Add these two angles to the two given interior angles, then set their sum to 360°360°
First, since the base angles in an isosceles triangle are equal, ∠ABE∠ABE is equal to 70°70°
∠ABE∠ABE
==
70°70°
Next, we can see from the diagram that the angle ∠ABE∠ABE and the angle ∠EBC∠EBC lie on a straight line. Therefore, they are supplementary angles
Since supplementary angles add to 180°,180°, add the angle measures and set their sum to 180°.180°. Then, solve for the value of ∠EBC∠EBC.
∠EBC+∠ABE∠EBC+∠ABE
==
180180
∠EBC+70∠EBC+70
==
180180
Plug in the known values
∠EBC+70∠EBC+70-70−70
==
180180-70−70
Subtract 7070 from both sides
∠EBC∠EBC
==
110°110°
Finally, since the interior angles of a quadrilateral add to 360°,360°, add the angle measures and set their sum to 360°.360°. Then, solve for ∠BED∠BED.