1.
What is the name for a triangle that has all three sides the same length?
Correct Answer
C. Equilateral
Explanation
An equilateral triangle is a type of triangle that has all three sides of the same length. In this triangle, all angles are also equal to 60 degrees. This makes it a special type of triangle with symmetrical properties.
2.
How would you name this triangle by its sides?
Correct Answer
B. Isosceles
Explanation
An isosceles triangle is a triangle that has two sides of equal length. In this case, since the question does not provide any information about the lengths of the sides, we can assume that two of the sides are equal. Therefore, the correct answer is "Isosceles."
3.
How would you name this triangle by its angles?
Correct Answer
C. Obtuse
Explanation
This triangle would be named "Obtuse" based on its angles. An obtuse triangle is a triangle that has one angle greater than 90 degrees. Since the question does not provide any information about the angles of the triangle, we can assume that it has at least one angle greater than 90 degrees, making it an obtuse triangle.
4.
How many degrees do the three angles of a triangle add up to?
Correct Answer
B. 180
Explanation
The three angles of a triangle always add up to 180 degrees. This is a fundamental property of triangles in Euclidean geometry. It can be proven using the fact that the sum of the angles in any polygon is equal to (n-2) * 180 degrees, where n is the number of sides of the polygon. Since a triangle has three sides, the sum of its angles is (3-2) * 180 = 180 degrees.
5.
If the three angles of a triangle measure 60, 80, and 40 degrees what type of triangle is it?
Correct Answer
A. Acute
Explanation
The three angles of a triangle measure 60, 80, and 40 degrees. In a triangle, the sum of all angles is always 180 degrees. Since the sum of these three angles is less than 180 degrees (60 + 80 + 40 = 180), the triangle is an acute triangle.
6.
If the sides of a triangle are 8 ft, 4 ft, and 5 ft what type of triangle is it?
Correct Answer
A. Scalene
Explanation
A scalene triangle is a triangle in which all three sides have different lengths. In this case, the given triangle has sides measuring 8 ft, 4 ft, and 5 ft, which are all different lengths. Therefore, it can be classified as a scalene triangle.
7.
If two of the angles in a triangle are 50 degrees and 100 degrees what is the third angle?
Correct Answer
D. 30 degrees
Explanation
The sum of the angles in a triangle is always 180 degrees. If two of the angles are 50 degrees and 100 degrees, the sum of these two angles is 150 degrees. To find the third angle, we subtract the sum of the two known angles from 180 degrees. Therefore, the third angle is 180 - 150 = 30 degrees.
8.
What type of triangle is shown below?
Correct Answer
D. Equilateral, Acute
Explanation
The given triangle is an equilateral triangle because all three sides are equal in length. Additionally, the triangle is acute because all three angles are less than 90 degrees.
9.
What is the name for a triangle that has a 90 degree angle?
Correct Answer
C. Right Triangle
Explanation
A triangle that has a 90 degree angle is called a right triangle. In a right triangle, one of the angles is a right angle, which measures 90 degrees. This means that one of the sides of the triangle is perpendicular to the other two sides.
10.
What makes a triangle Isosceles?
Correct Answer
B. Two of the sides are the same length
Explanation
An isosceles triangle is defined as a triangle that has two sides of equal length. Therefore, the correct answer is "Two of the sides are the same length." This is because in an isosceles triangle, the third side may or may not be of the same length as the other two sides.