454590 Triangles Page 1 of 5 Accompanying Resources: Printable Study Guide, Task Cards and Boom Cards What is a 454590 Triangle?
What do you know about a square? All 4 sides are the same length. Since a 454590 triangle is half of a square, this means that the two sides that form the 90 degree angle are the same length.
For this reason, a 454590 triangle is often referred to as an isosceles right triangle. If you know one of the legs of a 454590 triangle, the other leg will be the same. We know that one leg of this 454590 triangle is 7 units long. The two legs that form the right angle in a 454590 triangle are always the same length.
This means that x is also 7. 
