Fill in the blank help

The pyraminx is a rubik's cube-type toy in the shape of a tetrahedron. the pyraminx shown below has edges 15\,\text{cm}15cm long and vertical height h=12.2\,\text{cm}h=12.2cm. the triangle drawn with dashed lines is a right triangle. what is the distance rr? round your answer to the nearest tenth.

When you find the area of a triangle do you use in. or in2

Koda is making birdhouses for a park. the instructions tell him how many of each wooden shape is needed for one birdhouse. complete each statement to adjust the number of shapes for each new situation if he follows the given instructions. to make 8 birdhouses, koda will trapezoids.  for koda to make birdhouses, he will need 12 rectangles. if koda uses 4 squares to make birdhouses, he will use triangles.