The rule for regular polygons are very easy. The number of reflectional symmetries is same as the number of sides. Regular polygons have all sides the same length and all angles same. Reflection symmetry means that you can fold the shape along that line and it will match up.
For this question, we want the number of reflectional symmetries of a regular decagon. Decagon is a 10 sided figure. Hence, the number of reflectional symmetries is 10.
There are 5 symmetry lines from one vertex to opposite vertex and 5 more symmetry lines form midpoint of one side to midpoint of opposite side.
ANSWER: 10
Answer:
a) d = 36 ft. ( using Pithagoras´theorem )
b) d = 36 ft ( Using ( function sin ) trigonometry
Step-by-step explanation:
a) Using Pythagoras´Theorem:
Diagonal (d) is the hypothenuse of a right triangle of side 25 feet, and according to Pythagoras´Theorem in a right triangle.
d² = a² + b²
In this particular case a = b = 25 feet then
d² = (25)² + ( 25)²
d = √ 2 * (25)²
d = √2 * 25
d = 1,414*25
d = 35,35
d = 36 ft.
b) Using trigonometry:
We know that sin 45° = cos 45° = √2 / 2
In a right triangle
sin α = opposite side / hypothenuse (d)
sin 45° = √2 / 2 = 25/ d
√2 *d = 2* 25
d = 50/√2
d = 50 / 1,414
d = 35,36
d = 36 ft
Given:
angle of 6 : i'm assuming this is 6 degrees.
distance of 5 miles.
tan(6) = rise/5 mi
rise = 5 mi * tan(6)
rise = 5 mi * 0.10510423526
rise = 0.52552117632
rise = 0.53 miles.
