For #1 you have one leg of a right triangle measuring 4000 (the height of the mountain) and the other leg is 3000 (the distance that Mario is from Jenna). The angle of elevation is the one on the base of the triangle across from the right angle. To find the measure of the angle, use the tangent ratio: tan(A)=4000/3000, which could be simplified to tanA = 4/3. Do that on your calculator using the inverse tangent function to get that the angle of elevation from Mario to Jenna is 53 degrees.
For #2 you have another right triangle situation where the length of the hypotenuse is 20 and the base leg is 10. You are finding again the base angle across from the right angle. Use the cosA=10/20, aka cosA=.5. Again use the inverse cos function on your calculator to find the angle in question is 60 degrees.
No because 9/1,000 in decimals would be 0.009 because if the number was a 3 number then it would go in the tenths
Im not good at math so i use math-way.com
Area of a Circle: The area of a circle is the amount of space the circle takes up. To compute the area of a circle, we use the formula a=πr^2 where r is the radius of the circle.
Radius: The radius of a circle is the distance from the center of the circle to any point on the circle.