Find the measure of angle x in the figure below:

Two triangles are shown such that one triangle is inverted and they share a common vertex. The lower triangle has two angles at the base. The lower left angle is marked as 60 degrees. The lower right angle is marked as 50 degrees. The angle at the vertex of the inverted triangle at the top is marked as x degrees. The angle at the vertex of the bottom triangle is marked as y degrees.
60°
50°
110°
70°
Question 2
(Multiple Choice Worth 1 Points)
(02.04 MC)

Find the measure of angle x in the figure below:

A triangle is shown. At the top vertex of the triangle is a horizontal line aligned to the base of the triangle. The angle formed between the horizontal line and the left edge of the triangle is shown as 57 degrees, and the angle formed between the horizontal line and the right edge of the triangle is shown as 61 degrees. The angle at the top vertex of the triangle is labeled as y, and the interior angle on the right is labeled as 67 degrees. The interior angle on the left is labeled as x.
35°
47°
51°
62°
Question 3
(Multiple Choice Worth 1 Points)
(02.04 MC)

Given ΔMNO, find the measure of ∠LMN.

Triangle MNO with segment LM forming a straight angle with segment MO and segment OP forming a straight angle with segment MO, the measure of angle NOP is 104 degrees, and segment MN and NO are marked congruent.
38°
52°
76°
104°
Question 4
(Multiple Choice Worth 1 Points)
(02.04 MC)

triangle EFG in which segment EF measures 3 units and segment FG measures 5 units

In ΔEFG, is it possible for segment GE to measure 6 units?
Yes, because 3 + 5 > 6, 5 + 6 > 3, and 6 + 3 > 5
No, because 3 + 5 > 6, 5 + 6 > 3, and 6 + 3 > 5
Yes, because 3 + 5 < 6, 5 + 6 < 3, and 6 + 3 < 5
No, because 3 + 5 < 6, 5 + 6 < 3, and 6 + 3 < 5
Question 5
(Multiple Choice Worth 1 Points)
(02.04 LC)

A student states that a triangle can be formed with side lengths 4 in, 5 in, and 8 in. Is the student correct? Why, or why not?
Yes, because 4 + 5 > 8
Yes, because 5 + 8 < 4
No, because 4 + 5 > 8
No, because 5 + 8 > 4
Question 6
(Multiple Choice Worth 1 Points)
(02.04 LC)

Which of the following possibilities will form a triangle?
Side = 15 cm, side = 6 cm, side = 8 cm
Side = 15 cm, side = 6 cm, side = 9 cm
Side = 16 cm, side = 9 cm, side = 6 cm
Side = 16 cm, side = 9 cm, side = 8 cm
Question 7
(Multiple Choice Worth 1 Points)
(02.04 MC)

In ΔABC shown below, Line segment AB is congruent to Line segment BC:

Triangle ABC, where sides AB and CB are congruent

Given: line segment AB≅line segment BC

Prove: The base angles of an isosceles triangle are congruent.

The two-column proof with missing statement proves the base angles of an isosceles triangle are congruent:

Statement Reason
1. segment BD is an angle bisector of ∠ABC. 1. by Construction
2. ∠ABD ≅ ∠CBD 2. Definition of an Angle Bisector
3. 3. Reflexive Property
4. ΔABD ≅ ΔCBD 4. Side-Angle-Side (SAS) Postulate
5. ∠BAC ≅ ∠BCA 5. CPCTC

Which statement can be used to fill in the numbered blank space?
line segment BD≅line segment AC
line segment BD≅line segment BD
line segment AC≅line segment AC
line segment AD≅line segment DC
Question 8
(Multiple Choice Worth 1 Points)
(02.04 MC)

Find the measure of angle x in the figure below:

Two triangles are shown such that one triangle is inverted and share a common vertex. The lower triangle has two angles at the base marked as 75 degrees each. The angle at the vertex of the inverted triangle at the top is marked as x degrees.
15°
25°
30°
60°
Question 9
(Multiple Choice Worth 1 Points)
(02.04 MC)

Isosceles triangle ABC contains angle bisectors segment BF, segment AD, and segment CE that intersect at X.

triangle ABC with diagonals BF, AD, and EC that intersect at point X

If segment BA is congruent to segment BC and m∠BCA = 44°, what is m∠CXA?
136°
132°
68°
44°
Question 10
(Multiple Choice Worth 1 Points)
(02.04 MC)

Triangle ABC is shown below:

Triangle ABC. Line passes through points D, B, and E.

Given: ΔABC

Prove: All three angles of ΔABC add up to 180°.

The flowchart with missing reason proves the measures of the interior angles of ΔABC total 180°:

Top path, by Construction, line segment DE is parallel to line segment AC. By Alternate Interior Angles, angle EBC is congruent to angle BCA. By Substitution, the sum of the measures of angles BCA, CBA, and BAC equals 180 degrees. Next path, by Construction, line segment DE is parallel to line segment AC. By space labeled 1, angle DBA is congruent to angle BAC. By Substitution, the sum of the measures of angles BCA, BCA, and BAC equals 180 degrees. Next path, by Construction, line segment DE is parallel to line segment AC. By Definition of a Straight Angle, the measure of angle EBD equals 180 degrees. By Substitution, the sum of the measures of angles EBC, CBA, and DBA equals 180 degrees. Bottom path, by Construction, line segment DE is parallel to line segment AC. By Angle Addition Postulate, the sum of the measures of angles EBC, CBA, and DBA equals the measure of angle EBD. By Substitution, the sum of the measures of angles EBC, CBA, and DBA equals 180 degrees.

Which reason can be used to fill in the numbered blank space?
Alternate Exterior Angles Theorem
Same-Side Interior Angles
Corresponding Angles Postulate
Alternate Interior Angles Theorem

1 answer

Below are the answers to the questions:

Question 1:
To find angle \( x \):
The angles in a triangle sum to 180 degrees. For the lower triangle:
60° + 50° + angle \( y \) = 180°
Angle \( y = 180° - 60° - 50° = 70° \)
Angle \( x \) (the vertex angle of the inverted triangle) would be:
x + y = 180° (corresponding angles)
x + 70° = 180°
Thus, \( x = 180° - 70° = 110° \)
Answer: 110°


Question 2:
To find angle \( x \):
The top vertex angle \( y \) and the angles adjacent to it (57° and 61°) sum to 180°:
x + 57° + 61° = 180°
x + 118° = 180°
Thus, \( x = 180° - 118° = 62° \)
Answer: 62°


Question 3:
In triangle \( MNO \) with segment \( LM \) forming a straight angle with segment \( MO \). Given that \( \angle NOP = 104° \) and because segments \( MN \) and \( NO \) are congruent, this might lead us to utilize the Exterior Angle Theorem or consider \( \angle N + \angle M + \angle O = 180° \).
Since segment \( NO \) is congruent to segment \( MN \), \( \angle LMN \) would thus equal:
52°
Answer: 52°


Question 4:
To determine if segment \( GE \) can measure 6 units:
By triangle inequality, the sum of any two sides must be greater than the third side:

  • 3 + 5 > 6 (True)
  • 5 + 6 > 3 (True)
  • 6 + 3 > 5 (True)
    Thus, it is possible.
    Answer: Yes, because 3 + 5 > 6, 5 + 6 > 3, and 6 + 3 > 5

Question 5:
To check whether a triangle can be formed with side lengths 4 in, 5 in, and 8 in:
Verify the triangle inequality:

  • 4 + 5 = 9 (which is > 8)
    Therefore, the student is wrong because:
    Answer: No, because 4 + 5 = 9 > 8

Question 6:
We check the triangle inequality for each set of side lengths:

  1. 15 + 6 > 8 (True);
  2. 6 + 8 > 15 (False);
  3. 15 + 6 > 9 (True);
  4. 9 + 8 > 16 (False);
  5. 16 + 9 > 6 (True).
    Check set 1 works:
    Answer: Side = 15 cm, side = 6 cm, side = 8 cm

Question 7:
The missing statement relates to segments. Since segments \( BD \) must be reflexive, it leads to:
Answer: line segment BD ≅ line segment BD


Question 8:
To find angle \( x \):
The vertex angle sums with the base angles (which are equal) so:
x + 75° + 75° = 180°
x + 150° = 180°
Thus, \( x = 180° - 150° = 30° \)
Answer: 30°


Question 9:
Given that \( \angle BCA = 44° \) and since triangle \( ABC \) is isosceles where \( AB \cong BC \), the angles opposite these sides are equal. Thus:
m∠BCA + m∠BAC + m∠CBA = 180°
Let \( m∠BAC = m∠CBA \):
44° + 2x = 180°
2x = 136°
Thus, \( x = 68° \)
Answer: 68°


Question 10:
The flowchart details parallel lines help demonstrate that certain angles are equal through properties. The key reason involves angles that are congruent, leading to:
Answer: Alternate Interior Angles Theorem


These answers summarize and resolve the questions using geometrical principles related to triangles and their properties, ensuring clarity in the methodologies used.