CPM Homework Help : INT2 Problem 7-22

Jillian is trying to construct an isosceles right triangle. She has started by constructing two perpendicular lines, as shown at right. If she wants each leg of the triangle to have length $a$ as shown at right, describe how she should finish her construction.

Two perpendicular lines labeled, n, the vertical line, and, m, the horizontal line, intersect at point, P. A vertical line segment, k, is shown at the left.

Hint:

Where would either end of the hypotenuse end up?

More help:

How is point $P$ significant to the isosceles triangle?