Geometry Triangles & Congruence 3 — Questions and Answers
Question 1: In an isosceles triangle, the two angles opposite the equal sides are called what?
- Base angles (Correct answer)
- Vertex angles
- Right angles
- Exterior angles
Correct answer: Base angles
The angles opposite the congruent sides are the base angles and are equal.
Question 2: An equilateral triangle has how many degrees in each interior angle?
- 60 degrees (Correct answer)
- 90 degrees
- 45 degrees
- 120 degrees
Correct answer: 60 degrees
180 divided among three equal angles gives 60 degrees each.
Question 3: Which postulate uses two sides and the angle between them?
- SAS (Correct answer)
- ASA
- AAS
- SSS
Correct answer: SAS
Side-Angle-Side uses two sides with the included angle.
Question 4: The exterior angle of a triangle equals the sum of which angles?
- The two remote interior angles (Correct answer)
- All three interior angles
- The adjacent interior angle
- The two base angles only
Correct answer: The two remote interior angles
An exterior angle equals the sum of the two non-adjacent (remote) interior angles.
Question 5: Triangle DEF is congruent to triangle GHI. Which side corresponds to side DE?
- GH (Correct answer)
- HI
- GI
- EF
Correct answer: GH
Corresponding vertices in order give DE matching GH.
Question 6: What is the longest side of a triangle always opposite to?
- The largest angle (Correct answer)
- The smallest angle
- The right angle only
- The midpoint
Correct answer: The largest angle
In any triangle, the longest side lies opposite the largest angle.
Question 7: Can a triangle have sides of length 2, 3, and 6?
- No, it violates the triangle inequality (Correct answer)
- Yes, it is scalene
- Yes, it is obtuse
- Yes, it is right
Correct answer: No, it violates the triangle inequality
Since 2 + 3 = 5 is less than 6, the triangle inequality fails.
Geometry Triangles & Congruence 3
In an isosceles triangle, the two angles opposite the equal sides are called what?