# Isosceles Triangles (Part Two)

Taught by MrRutter
• Currently 3.0/5 Stars.
7205 views | 2 ratings
Part of video series
Meets NCTM Standards:
Lesson Summary:

In this lesson on isosceles triangles, we learn how to find the angles of a picture of triangles using concepts such as straight lines adding to 180, angles in a triangle making 180, and the exterior angle equaling the sum of the two interior angles. By using these concepts, we can find every other angle in a shape where certain sides and angles are congruent. This lesson provides a clear and concise demonstration of how to solve for unknown angles in a variety of different triangles.

Lesson Description:

Learn how to find out the angles of a picture of triangles.

• How do find angles if you have a picture with a bunch of triangles touching each other?
• How do you find the angle measures if you just have a picture with tick marks?
• How do you find angle measures in a picture with isosceles and equilateral triangles bunched together?
• What is each angle measure in an equilateral triangle?
• How many degrees are in a straight line?
• If you know two angles in a triangle, how do you find the third angle?
• If you know one angle in an isosceles triangle, how do you find the other two?
• How do you find angle measures in a diagram if you do not start with any angle measures?
• #### Staff Review

• Currently 3.0/5 Stars.
This video finishes off the problem introduced in Part 1 of Isosceles Triangles. This is a rather daunting problem at first glance, and it uses a lot of prior knowledge about angles and isosceles triangles. This is a great wrap-up problem to a section on angles and triangles.