The diagram shows a sector of a circle radius 10cm. Find the perimeter of the sector, giving your answer correct to 1 decimal place

In triangle abc, the length of side ab is 12 cm, the length of side bc is 5 cm, and the length of side ca is 9 cm. find the measure of angle a using the law of cosines.

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.

Hilary decided to purchase 3 points in order to lower her interest rate on her $140,000 mortgage. how much additional money does she need to bring to closing? a. $4200 b. $4000 c. $6 d. $400