Question

Preston has calculated that his drink coaster has an area of 78.5 square centimeters.What is the coaster’s radius? Use 3.14 for pi

Answer 1

Answer:

The coaster’s radius is 5 cm

Step-by-step explanation:

Drink Coaster has a circular shape.

Area of a circle = π*r²

so, area of the drink coaster = π x (Radius of the drink coaster)²

Given that Area of the drink coaster is 78.5 cm²

∴ 78.5 cm² = π*r²

Also we are to use 3.14 for π

∴ 78.5 cm² = 3.14*r²

   r² = 78.5 cm² / 3.14

   r² = 25 cm²

   r = $\sqrt{25}$ cm

   r = 5 cm

Hence, the coaster’s radius is 5 cm