ABCDEFGHIJ is a regular decagon with a radius of 25.89 units. Find the area of ABCDEFGHIJ. Round the answer to the nearest tenth

Question

tatyana61 [14]

2 years ago

6

ABCDEFGHIJ is a regular decagon with a radius of 25.89 units. Find the area of ABCDEFGHIJ. Round the answer to the nearest tenth

. A. 123.1 square units B. 769.4 square units C. 1,969.7 square units D. 7,878.9 square units

Mathematics

1 answer:

Verdich [7] · Answer 1 · 2022-07-01T07:11:47+03:00

Verdich [7]2 years ago

6 0

Let's call the midpoint of GF M.
MF = 16/2 = 8
KF = 25.89
MK = sqrt(25.89^2 - 8^2)
MK = 24.62
MKF = 8 * 24.62 / 2 = 98.48 square units for one triangle
There are 20 of those triangles that make up the decagon.
Therefore the total area = 20(98.48) = 1969.6 which would be option C