Exploring Triangles: Sides and Angles

Exploring Triangles

Understanding the sides and angles of triangles

Classifying Triangles

Triangles can be classified based on their sides and angles. The sides can be classified as equilateral (all sides are equal), isosceles (two sides are equal), or scalene (no sides are equal). The angles can be classified as acute (all angles are less than 90 degrees), right (one angle is exactly 90 degrees), or obtuse (one angle is greater than 90 degrees).

Triangle Theorems

Multiple Choice

Which type of triangle has all sides equal?

• Equilateral triangle

• Isosceles triangle

• Scalene triangle

• Right triangle

Match

Match the following triangle with the correct classification

Isosceles acute

Scalene obtuse

scalene right

equalateral acute

Isosceles right

• Isosceles acute

• Scalene obtuse

• scalene right

• equalateral acute

• Isosceles right

Multiple Choice

Which theorem states that the sum of the angles in triangle is 180 degrees?

• Triangle Inequality Theorem

• Triangle Angle Sum Theorem

• Pythagorean Theorem

• Law of Sines

Triangle Angle Sum Theorem

Multiple Choice

What is the measure of angle C in the given triangle

if m∠A = 30 and  m∠B = 70; what is m∠C ??

• 50 degrees

• 60 degrees

• 70 degrees

• 80 degrees

Multiple Choice

What is the value of x and y ?

• 39

• 41

• 45

• 50

Multiple Choice

Which theorem states that the sum of the two shortest sides of a triangle is greater than the longest side?

• Triangle Inequality Theorem

• Triangle Angle Sum Theorem

• Pythagorean Theorem

• Law of Sines

Triangle Inequality Theorem

Multiple Choice

Which three length create a triangle?

• 3,3,6

• 40 ,50,60.1

• 4.5, 5.5, 10

• 20, 30,50

Multiple Choice

What is the range of possible third side measures using 10 and 15?

• 10<x<15

• 10>x>15

• 5<x<25

• 5>x>25

Multiple Choice

Which length would be the possible third side given the length 10 and 15?

• 5

• 25

• 10

• 26