Isosceles Triangles (open ended)

Front

What is an isosceles triangle?

Back

An isosceles triangle is a triangle that has at least two sides of equal length.

Front

What are the properties of an isosceles triangle?

Back

1. Two sides are equal in length. 2. The angles opposite the equal sides are also equal.

Front

How do you classify triangles based on angles?

Back

Triangles can be classified as acute (all angles < 90°), right (one angle = 90°), or obtuse (one angle > 90°).

Front

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

Back

The sum of the interior angles of a triangle is always 180 degrees.

Front

If two angles of a triangle are equal, what can be said about the triangle?

Back

The triangle is isosceles.

Front

What is the formula to find the area of a triangle?

Back

Area = 1/2 * base * height.

Front

In an isosceles triangle, if the equal sides are 10 cm each and the base is 8 cm, what is the height?

Back

Height = √(10² - (8/2)²) = √(100 - 16) = √84 ≈ 9.17 cm.

Front

What is the relationship between the angles in an isosceles triangle?

Back

The angles opposite the equal sides are equal.

Front

How do you find the missing angle in a triangle?

Back

Subtract the sum of the known angles from 180 degrees.

Front

What is a right isosceles triangle?

Back

A right isosceles triangle has one angle that is 90 degrees and the two other angles are 45 degrees each.