Isosceles Triangle Properties and Angles

What is a key characteristic of an isosceles triangle?

• It has no equal sides.

• All angles are 90 degrees.

• Two sides and two base angles are equal.

• All three sides are equal.

How can you identify an isosceles triangle?

• By ensuring all sides are different.

• By looking for two equal sides and two equal base angles.

• By checking if all angles are equal.

• By finding one right angle.

How do you denote the base angles of an isosceles triangle in geometric reasoning?

• Base angles of equal sides

• Equal angles of triangle

• Angles of isosceles

• Base angles of isos triangle

In the first example, what is the value of X if the base angles are equal and one base angle is 50°?

• 30°

• 50°

• 60°

• 70°

What do the two little lines on the sides of a triangle indicate?

• The sides are different.

• The sides are equal.

• The angles are different.

• The angles are equal.

In the second example, if one base angle is 20°, what is the value of X?

• 120°

• 140°

• 160°

• 180°

What is the sum of angles in any triangle?

• 360°

• 270°

• 180°

• 90°

In the third example, what is the value of X if the base angles are equal and the third angle is 80°?

• 60°

• 40°

• 50°

• 70°

What does the presence of double lines on the sides of a triangle indicate?

• The angles are equal.

• The angles are different.

• The sides are equal.

• The sides are different.

What geometric rule is used along with the isosceles triangle property to solve for unknown angles?

• Sum of angles in a triangle

• Sum of angles in a square

• Sum of angles in a circle

• Sum of angles in a rectangle