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26 votes
Quadrilateral ABCD has the following angle measures:

m∠A = 105°, m∠B = ?°, m∠C = 34°, m∠D = 90°

What is m∠B?


pleeeeease help!!

User Ben Hillier
by
2.9k points

2 Answers

25 votes
25 votes

Answer:

The measure of m<GHE is 49°, the correct option is B.

What is a Quadrilateral?

A quadrilateral is a polygon with four sides.

It is of various types,

Trapezoid, which have one pair of parallel sides,

Parallelogram, it has two pairs of parallel sides,

Rhombus, it has all sides equal,

Rectangle, opposite sides are parallel and equal, and,

Square, all sides are equal and opposite sides are parallel, and all angles have measure of 90 degree.

The quadrilateral ABCD is ≅ quadrilateral EFGH

When two figures are congruent then by CPCTC, corresponding parts of congruent figures are congruent.

The measure of the angle

B = m<BCD = 90°

m<BAD = 131°

As the quadrilaterals are congruent,

By CPCTC

∠F = ∠FGH = 90°

m ∠FEH = 131°

The measure of m<GHE has to be determined.

The sum of the measures of all angle so of a quadrilateral is 360 degree.

The ∠F + ∠FGH + ∠FEH + ∠GHE = 360

90 +90+ 131 +∠GHE = 360

∠GHE = 49°

Explanation:

User Jredburn
by
3.0k points
15 votes
15 votes

Answer:

131°

Explanation:

Sum of all angles of a quadrilateral = 360°

We can find the unknown angle ∠B, by subtracting the sum of the angles ∠A, ∠C, ∠D from 360°.

∠A + ∠B + ∠C + ∠D = 360

105 + ∠B + 34 + 90 = 360

∠B + 229 = 360

∠B = 360 - 229

∠B = 131°

User Opy
by
2.5k points