All ACT Math Resources
Example Questions
Example Question #51 : Right Triangles
Find the length of the hypotenuse.
Note: This is a right triangle.
To find the length of this hypotenuse, we need to use the Pythagorean Theorem:
, where a and b are the legs and c is the hypotenuse.
Here, c is our missing hypotenuse length, a = 4 ,and b = 14.
Plug these values in and solve for c:
Example Question #71 : Right Triangles
Side in the triangle below (not to scale) is equal to . Side is equal to . What is the length of side ?
Use the Pythagorean Theorem: , where a and b are the legs and c is the hypotenuse.
We know and , so we can plug them in to solve for c:
Example Question #72 : Right Triangles
Dan drives 5 miles north and then 8 miles west to get to school. If he walks, he can take a direct path from his house to the school, cutting down the distance. How long is the path from Dan's house to his school?
89 miles
13 miles
19 miles
4.36 miles
9.43 miles
9.43 miles
We are really looking for the hypotenuse of a triangle that has legs of 5 miles and 8 miles.
Apply the Pythagorean Theorem:
a2 + b2 = c2
25 + 64 = c2
89 = c2
c = 9.43 miles
Example Question #63 : Right Triangles
What is the hypotenuse of a right triangle with side lengths and ?
The Pythagorean Theorem states that . This question gives us the values of and , and asks us to solve for .
Take and and plug them into the equation as and :
Now we can start solving for :
The length of the hypotenuse is .
Example Question #61 : Triangles
One leg of a triangle measures 12 inches. Which of the following could be the length of the other leg if the hypotenuse is an integer length?
By the Pythagorean Theorem, if is the hypotenuse and and are the legs, .
Set , the known leg, and rewrite the above as:
We can now substitute each of the five choices for ; the one which yields a whole number for is the correct answer choice.
:
:
:
:
:
The only value of which yields a whole number for the hypotenuse is 16, so this is the one we choose.
Example Question #41 : How To Find The Length Of The Hypotenuse Of A Right Triangle : Pythagorean Theorem
Find the perimeter of the polygon.
Divide the shape into a rectangle and a right triangle as indicated below.
Find the hypotenuse of the right triangle with the Pythagorean Theorem, , where and are the legs of the triangle and is its hypotenuse.
This is our missing length.
Now add the sides of the polygon together to find the perimeter:
Example Question #42 : How To Find The Length Of The Hypotenuse Of A Right Triangle : Pythagorean Theorem
The lengths of the sides of a right triangle are consecutive integers, and the length of the shortest side is . Which of the following expressions could be used to solve for ?
Since the lengths of the sides are consecutive integers and the shortest side is , the three sides are , , and .
We then use the Pythagorean Theorem:
Example Question #73 : Right Triangles
Square is on the coordinate plane, and each side of the square is parallel to either the -axis or -axis. Point has coordinates and point has the coordinates .
Quantity A:
Quantity B: The distance between points and
Quantity B is greater.
The relationship cannot be determined from the information provided.
Quantity A is greater.
The two quantities are equal.
The two quantities are equal.
To find the distance between points and , split the square into two 45-45-90 triangles and find the hypotenuse. The side ratio of the 45-45-90 triangle is , so if the sides have a length of 5, the hypotenuse must be .
Example Question #124 : Geometry
What is the diagonal of a computer screen that measures inches tall by inches wide?
Plug the values into the Pythagorean Theorem
,
because we are solving for the diagonal we are looking for .
.
.
Example Question #131 : Geometry
A right triangle has legs of length and , what is the length of the hypotenuse?
To find the hypotenuse of a right triangle, use the Pythagorean Theorem and plug the leg values in for and :
Certified Tutor