Exploring Isosceles and Equilateral Triangle Theorems

The video tutorial from Friendly Math 101 covers the isosceles and equilateral triangle theorems. It explains that in an isosceles triangle, two sides are equal, leading to equal opposite angles. In an equilateral triangle, all sides and angles are equal, with each angle measuring 60 degrees. The tutorial includes three example problems: finding angles in an isosceles triangle, using the exterior angle theorem, and solving for side lengths using angle equality. The video concludes with a prompt to subscribe for more math tutorials.

What is the main topic of today's lesson?

• Quadratic Equations

• Circle Theorems

• Isosceles and Equilateral Triangle Theorems

• Pythagorean Theorem

Tags

CCSS.8.G.B.8

According to the isosceles triangle theorem, if two sides of a triangle are equal, what can be said about the angles opposite these sides?

• They are supplementary

• They are equal

• They are right angles

• They are complementary

Tags

CCSS.8.G.B.8

In an equilateral triangle, what is the measure of each angle?

• 45 degrees

• 60 degrees

• 90 degrees

• 120 degrees

Tags

CCSS.8.G.A.5

In an equilateral triangle, if one side is 5 cm, what is the length of the other sides?

• 6 cm

• 4 cm

• 3 cm

• 5 cm

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CCSS.2.G.A.1

If a triangle has two sides of equal length, what type of triangle is it?

• Equilateral

• Isosceles

• Right

• Scalene

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CCSS.4.G.A.2

In an isosceles triangle with angles 75 degrees and 75 degrees, what is the measure of the third angle?

• 90 degrees

• 30 degrees

• 45 degrees

• 60 degrees

Tags

CCSS.8.G.A.5

If a triangle has sides of lengths 3x - 1 and 5x - 29, and these sides are equal, what is the value of x?

• 10

• 12

• 14

• 16

Tags

CCSS.8.G.A.5

In an isosceles triangle, if one of the equal angles is 78 degrees, what is the measure of the other equal angle?

• 156 degrees

• 102 degrees

• 78 degrees

• 24 degrees

Tags

CCSS.8.G.A.5

What is the sum of the interior angles of any triangle?

• 270 degrees

• 360 degrees

• 180 degrees

• 90 degrees

Tags

CCSS.8.G.A.5

If the exterior angle of a triangle is 102 degrees and one of the remote interior angles is 24 degrees, what is the measure of the other remote interior angle?

• 24 degrees

• 48 degrees

• 78 degrees

• 102 degrees

Tags

CCSS.8.G.A.5