19. Perimeter of rectangle = 2(l + b)
l = 25m
b = 16m
Perimeter of rectangular park = 2 (25 + 16)
= 50 + 32
= 82m
Perimeter of square park = 82m
(given that, perimeter of rectangular and square park are equal)
Perimeter of square = 4a
4a = 82
a = 82/4
a = 20.5m
Area of square park = a²
= 20.5²
= 420.25m²
20. Perimeter of regular hexagon = 6a
a = 2.5
6a = 6 × 2.5
= 15cm
21. Perimeter of regular decagon = 10a
a = 8
10a = 10 × 8
= 80cm
For each of these problems, remember SOH-CAH-TOA.
Sine = opposite/hypotenuse
Cosine = adjacent/hypotenuse
Tangent = opposite/adjacent
5) Here we are looking for the cosine of the 30 degree angle. Cosine uses the adjacent side to the angle over the hypotenuse. Therefore, cos(30) = 43/50.
6) We have an unknown side length, of which is adjacent to 22 degrees, and the length of the hypotenuse. Since we know the adjacent side and the hypotenuse, we should use Cosine. Therefore, our equation to find the missing side length is cos(22) = x / 15.
7) When finding an angle, we always use the inverse of the trigonometry function we originally used. Therefore, if sin(A) = 12/15, then the inverse of that would be sin^-1 (12/15) = A.
8) We are again using an inverse trigonometry function here. We know the hypotenuse, as well as the side adjacent to the angle. Therefore, we should use the inverse cosine function. Using the inverse cosine function gives us cos^-1 (9/13) = 46 degrees.
Hope this helps!
Well, there are 3 feet in a yard. So, 3ft=1yrd. Multiply the length value by 3. You could also multiply 3 by the # of yards (or in this situation, 8) Is that good enough?
What are the answer options?
