Question 144260
Drop a segment from the vertex at the right triangle down and intersect hypotenuse. What is the measure of both segments on the original hypotenuse? Right it cuts it in half , so they are both 8cm

This results in two new isosceles triangle (they also each are right triangles, with other angles equal to 45).

What do you know about the sides of an isosceles triangle? What can you say about the length of segment you just drew in? Right, that too is 8cm.

So now you have a base of 16cm and a height of 8cm.