As the regular pentagon there is 5 regular triangles.
And the area of 1 regular triangle is:
At = Side^2 × √(3)/4
But, as the pentagon has 5 triangle
Then,
Ap = 5 × Side^2 . √(3)/4
Replacing Ap = 6.9
5 × Side^2 . √(3)/4 = 6.9
Side^2 . √(3)/4 = 6.9 ÷ 5
Side^2 . √(3) = 4 × 1,38
Side^2 = 5,52 ÷ √(3)
Side^2 = 3,187
Side = √(3,187)
Side = 1,785 cm
Then,
The total perimeter will be:
P = 5 × Side
P = 5 × 1,785
P = 8,92 cm
Well, I did find this answer.
The area of the cross-section is 169 sq. cm.
That is the correct answer to this problem
Answer:
20
Step-by-step explanation:
Since you can use the Pythagorean theorem to calculate the length of the hypotenuse, each side can be found to be 5. There are four equal sides, so it is 20.