Triangles Finding Missing Angles

Front

What is a triangle?

Back

A triangle is a polygon with three edges and three vertices.

Front

What are the types of triangles based on angles?

Back

1. Acute Triangle: All angles are less than 90 degrees. 2. Right Triangle: One angle is exactly 90 degrees. 3. Obtuse Triangle: One angle is greater than 90 degrees.

Front

What is the sum of the angles in a triangle?

Back

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

Front

How do you find a missing angle in a triangle?

Back

To find a missing angle, subtract the sum of the known angles from 180 degrees.

Front

What does it mean for triangles to be similar?

Back

Triangles are similar if they have the same shape but not necessarily the same size. This means their corresponding angles are equal and their sides are in proportion.

Front

If two triangles have one angle equal and the sides around that angle in proportion, what can we conclude?

Back

The triangles are similar by the Angle-Side-Angle (ASA) similarity criterion.

Front

What is the Angle-Angle (AA) similarity criterion?

Back

If two angles of one triangle are equal to two angles of another triangle, the triangles are similar.

Front

How can you determine if two triangles are similar using side lengths?

Back

If the ratios of the lengths of corresponding sides of two triangles are equal, then the triangles are similar.

Front

What is the measure of the missing angle if two angles are 47 degrees and 53 degrees?

Back

The missing angle is 80 degrees (180 - 47 - 53 = 80).

Front

If triangle A has angles of 30 and 60 degrees, what is the measure of the third angle?

Back

The third angle is 90 degrees (180 - 30 - 60 = 90).