Alex wants to make birdhouses for the wild birds that lives around the area. she's trying to decide on the measurements for the roof of a birdhouse. the diagram shows that the roof is formed by two identical right triangles. which set of measurements can be used to make one of the right triangles?

a. 15 cm, 20 cm, 35 cm
b. 15 cm, 36 cm, 39 cm
c. 15 cm, 20 cm, 26 cm
d. 12 cm, 16 cm, 18 cm