Answer: first option 392.699 square feet.
Explanation:
1) The shape of the sidewalk is an ring with exterior radius equal to the radious of the fountain + 5 feet and inner radius equal to the radius of the fountain.
2) The area of such ring is equal to the area of the outer circle less the area of the inner circle (the fountain)
Area of a circle = π × r²
Area of the outer circle: π (10ft + 5 ft)² = π (15 ft)² = 225 π ft²
Area of the inner circle = π (10ft)² = 100 π ft²
Area of the ring (sidewald) = 225π ft² - 100π ft² = 125π ft² = 392.699 ft²
Answer:
-7°C
Step-by-step explanation:
Freezing point of water = 0°C
By adding salt, freezing point lowers by 7°C ;
The freezing point of salt water can be expressed as ;
Since temperature lowers :
Freezing point of salt water :
Freezing point of water - 7°C
0°C - 7°C
= - 7°C
There you go hope this helps
Answer:
the answer is 11/21 or 0.523809524
hope this helped
Step-by-step explanation:
