The best answer is:
A. Helping immigrants and the poor at Hull House - She opened it in Chicago in 1889
hope this helped :)
Answer:
s = 16.97 units
Step-by-step explanation:
Since this is a right triangle, we can use trigonometry to figure out the lengths of the sides.
Look at the 45 degree angle. We can use the opposite side (12) and the hypotenuse (s) to solve for s.
Opposite and hypotenuse is sine, so we are using sine. The sine of 45 degrees is 0.70710678118. Make an equation like so:
- 0.70710678118 = , and we are solving for s.
Put a 1 in the denominator of sine(45 degrees) so you can cross-multiply.
Cross multiply.
Divide both sides by sine(45 degrees).
The length of side s is 16.97 units.
Another way to have done this problem is to use the Pythagorean theorem: a^2 + b^2 = c^2
Substitute 12 for a and b and solve for c, the hypotenuse.
Evaluate the exponents.
Add them together.
Square root 288 to solve for c.
c = 16.97, which is the same answer as you got using trigonometry.
Here, we have been asked to find the order of rotational symmetry of a symmetry of a regular pentagon. First let us learn about rotational symmetry and some basic terms related to it.
1. Rotational Symmetry: -
It is the property a shape has when it looks the same after some rotation by a partial turn. For example: - an equilateral triangle will look the same after a partial rotation of 120∘
2. Centre of rotation: -
The fixed point around which the rotation occurs is called the centre of rotation. For example: - the centre of rotation of a fan is the centre of the fan from which its blade originates.
3. Angle of Rotational Symmetry: -
The angle of rotational symmetry is the smallest angle for which the figure can be rotated to coincide with itself. For example: - the angle of rotation of an equilateral triangle is 120∘
4. Order of Rotational Symmetry: -
The order of rotational symmetry of a shape is the number of times it can be rotated around a full circle and still look the same. For example: - an equilateral triangle can be rotated 3 times around a full circle, each time at the angle of 120∘
, so its order of rotation will be 3.
In general, a regular polygon having n – sides have ‘n’ lines of symmetry and their order of rotational symmetry is ‘n’.
Now, let us come to the question. We have to find the order of rotational symmetry of a regular pentagon.
We know that a regular pentagon has 5 sides.
<h3> Hence, it will have 5 lines of symmetry and its order of rotational symmetry will be 5.</h3>
Answer:
B is the answer
Step-by-step explanation: