Answer:
79 units²
Step-by-step explanation:
The area of a circle is found by using the formula A = π x r². Since we are not given the radius we can use the formula r = C / (2π). Substituting in the given values, we get r = 31.5/(2π). 2 times pi is 6.283185307. 31.5 divided by this will get you 5.013380707. Now, put that value in for r in the area equation. A = π x 5.013380707². Pi times 5.013380707² equals 78.96074613. This can be rounded to 79. (Or 80 if you need to the nearest whole number.)
Answer:
115
Explanation:
Angles in a triangle sum to 180
Add the two angles given and subtract it from the total sum of angles to find the missing interior angle -
75 + 40 = 115
180 - 115 = 65
Now that we have the interior angle, we can work out the exterior angle by subtracting it from 180
180 - 65 = 115
Answer:
Step-by-step explanation:
volume of a sphere 4/3 pi r^3
vol=4/3 pi 20^3
= 4/3 x 3.1415x 8000
= 33510km^3
