Are these fractions equivalent to 4/9?

20/36
8/18
24/45
12/27

Marina baked cookies. she gave 3/4 of the cookies to the scout bake sale. she shared the remaining 6 cookies with her friends. how many cookies did marina bake?

Aplane intersects a pris paralel to the base of the prism. the cross section is a polygon wth eight sides. how many sides does the base of the prism have? a. 10 b. 8 c. 7 d. 9

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.