The Broken Pinwheel block is made with tri square triangle units using 3 fabrics and is set in a 2 by 2 square grid. There is a subtle difference between quarters of this block, so pay careful attention to how the quarter square triangles are sewn together.
The Whirlwind block uses half square triangle and quarter square triangle pieces to make a sailboat unit or what I like to call a tri square triangle unit. You'll need 2 fabrics, a half square triangle ruler and a quarter square triangle ruler to make this block.
The Card Tricks block is made with half, tri and quarter square triangle units using 3 fabrics. This block fits a 3 by 3 square grid layout. We'll be using right triangle rulers to cut from strips.
A Card Tricks calculator is available for different sizes, number and methods of blocks for your own project.