Answer:
752.4
Step-by-step explanation:
Here we are provided with a decagon which has 10 sides.
The total interior angle is 360°.
So each will have 360/10 = 36 degrees
Half of that is 18 degrees inside the triangle.
Refer to the attachment below.
opposite = 16sin(18)
adjacent = 16cos(18)
Find the area of this triangle:
= 1/2 × 16sin(18) × 16cos(18)
= 37.61825
There are 20 triangles just like this so the total area is (37.61825 × 20) = 752.365 ≈ 752.4 unit2
