All ACT Math Resources
Example Questions
Example Question #1 :45/45/90 Right Isosceles Triangles
The area of an isosceles right triangle is. What is its height that is correlative and perpendicular to a side that is not the hypotenuse?
Recall that an isosceles right triangle is atriangle. That means that it looks like this:
This makes calculating the area very easy! Recall, the area of a triangle is defined as:
However, sincefor our triangle, we know:
Now, we know that. Therefore, we can write:
Solving for, we get:
This is the length of the height of the triangle for the side that is not the hypotenuse.
Example Question #2 :45/45/90 Right Isosceles Triangles
What is the area of an isosceles right triangle that has an hypotenuse of length?
Based on the information given, you know that your triangle looks as follows:
This is atriangle. Recall your standardtriangle:
You can set up the following ratio between these two figures:
Now, the area of the triangle will merely be(since both the base and the height are). For your data, this is:
Example Question #3 :45/45/90 Right Isosceles Triangles
Find the height of an isoceles right triangle whose hypotenuse is
To solve simply realize the hypotenuse of one of these triangles is of the formwhere s is side length. Thus, our answer is.
Example Question #4 :45/45/90 Right Isosceles Triangles
The area of an isosceles right triangle is. What is its height that is correlative and perpendicular to this triangle's hypotenuse?
Recall that an isosceles right triangle is atriangle. That means that it looks like this:
This makes calculating the area very easy! Recall, the area of a triangle is defined as:
However, sincefor our triangle, we know:
Now, we know that. Therefore, we can write:
Solving for, we get:
However, be careful! Notice what the question asks: "What is its height that is correlative and perpendicular to this triangle's hypotenuse?" First, let's find the hypotenuse of the triangle. Recall your standardtriangle:
Since one of your sides is, your hypotenuse is.
Okay, what you areactuallylooking for isin the following figure:
Therefore, since you know the area, you can say:
Solving, you get:.