Discover the best answers to your questions with the help of IDNLearn.com. Find the answers you need quickly and accurately with help from our knowledgeable and experienced experts.
The angle BCD = 120°
Given
A parallelogram and four angles
Required
Angle BCD
Solution
In A parallelogram
The sum of the four angles is 360°
Opposite angles are equal /congruent(A=C, B=D)
Consecutive angles are supplementary (A + D = 180 °, D + C = 180°, C + B = 180°, B + A = 180°).
We choose a solution by using
Consecutive angles :
∠C+∠B=180°
18x=180°
x=10
∠C=∠BCD =
[tex]\tt 12x=12\times 10=120^o[/tex]
Or we can use another ways :
The sum of the four angles is 360°
∠A+∠B+∠C+∠D=360°
12x+6x+12x+6x=360°
36x=360°
x=10
∠C=∠BCD =
[tex]\tt 12x=12\times 10=120^o[/tex]