Bcde is a parallelogram. what is the measure of ∠bec? enter your answer in the box. ° a parallelogram b c d e. side e d is the base. the pairs of opposite sides are parallel. diagonal e c divides the parallelogram into triangles c d e and b c e. angle b is labeled 60 degrees and angle c e d is labeled 40 degrees.

Solution:

In Parallelogram B CDE

BC= DE, BC ║DE

CD = BE , CD ║BE

Also, ∠B=∠D and ∠C=∠E →→In a parallelogram opposite sides are equal and parallel, as well as opposite angles are equal.Diagonals Bisect each other.

∠B= 60° , ∠C ED= 40°

CE is a transversal and BC║DE.

∠CED=∠BCE = 40° →→Alternate interior angles

In Δ BCE

∠B + ∠BCE + ∠BEC= 180°→→→Angle sum property of Triangle.

60° + 40° + ∠ B E C= 180°

100° + ∠BEC=180°

∠BEC= 180° -100°

∠BEC= 80°

∠1≅∠2 by the alternate exterior angles theorem.

step-by-step explanation:

given, a ∥ b and ∠1 ≅ ∠3 .we have to prove that e ∥ f

we know that ∠1≅∠3 and that a || b because they are given. we see that by the alternate exterior angles theorem. therefore, ∠2≅∠3 by the transitive property. so, we can conclude that e || f by the converse alternate exterior angles theorem.

we have to fill the missing statement.

transitivity property states that if a = b and b = c, then a = c.

now, given ∠1≅∠3 and by transitivity property ∠2≅∠3 .

hence, to apply transitivity property one angle must be common which is not in result after applying this property which is ∠1.

the only options in which ∠1 is present are ∠1 and ∠2, ∠1 and ∠4

∠1 and ∠4 is not possible ∵ after applying transitivity we didn't get ∠4.

hence, the missing statement is ∠1≅∠2.

so, ∠1≅∠2 by the alternate exterior angles theorem.

the answer is d

the answer is in the first quadrant, which make the y-int positive.

since the dots are going down, therefore the correlation is negative

i hope it is right.