Right Triangles
A right triangle is identified because it has an interior angle of 90° (right angle). The other two angles must be acute and add up to 90°.
In the special case that both acute angles have a measure of 45°, then we have an isosceles triangle, that is, both legs have the same length.
We can see one of the legs measures
Being this an isosceles triangle, the other leg (the base of the triangle) also measures L, thus you should drag
To the box at the bottom.
The other unknown length is the hypotenuse H. According to the Pythagorean's Theorem:
Substituting:
You should drag the length 10 to the hypotenuse.