Answer:
Two triangles are congruent if they have: exactly the same three sides and. exactly the same three angles
There are five ways to find if two triangles are congruent: SSS, SAS, ASA, AAS and HL.
SSS (side, side, side) ...
SAS (side, angle, side) ...
ASA (angle, side, angle) ...
AAS (angle, angle, side) ...
HL (hypotenuse, leg)
Answer:
There are total 30 books in the 5 feet high stack of books.
Step-by-step explanation:
The complete question is
Given, Each note book is 2 inches thick, How many notebooks do you think it would take to make a stack that is 5 feet high
Solution
Thickness of each book 
The total height of the book stack is
feet.
The number of books in the stack is equal to total height of the stack divided by the thickness of one book
Number of books in five feet high stack is

Hence, there are total 30 books in the 5 feet high stack of books.
Answer:
50
Step-by-step explanation:
1. 567
2. 33
3. 85%; $17
4. they have 4 pages left
5. (-5,2)
Answer: The sailboat is at a distance of 15 km from the port.
Step-by-step explanation: Given that a sail boat leaves port and sails 12 kilometers west and then 9 kilometers north.
We are to find the distance between the sailboat from the port in kilometers.
Since the directions west and north are at right-angles, we can visualize the movement of the sailboat in the form of a right-angled triangle as shown in the attached figure.
The sailboat moves leaves the port at P and reach O after sailing 12 km west. From point O, again it moves towards north 9 km and reach the point S.
PS = ?
Using the Pythagoras theorem, we have from right-angled triangle SOP,
Thus, the sailboat is at a distance of 15 km from the port.