Basic Geometry : Right Triangles
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Example Questions
Example Question #1383 : Plane Geometry
Given that:
A = 10 cm
B = 20 cm
What is the area of the right triangle ABC?
70 square centimeters
30 square centimeters
100 square centimeters
120 square centimeters
50 square centimeters
100 square centimeters
The area of a triangle is given by the equation:
Since the base leg of the given triangle is 4 cm, while the height is 3 cm, this gives:
Example Question #5 : How To Find The Area Of A Right Triangle
The length of the legs of the triangle below (not to scale) are as follows:
What is the area of the triangle?
The formula for the area of a triangle is
where 
For the triangle shown, side 
Therefore, the area is equal to
or, based on the units given, 42 square centimeters
Example Question #5 : How To Find The Area Of A Right Triangle
An equilateral triangle has a side of 
What is the area of the triangle?
An equilateral triangle has three congruent sides. The area of a triangle is given by 
The equilateral triangle can be broken into two 
Using the Pythagorean Theorem we get 
Example Question #4 : How To Find The Area Of A Right Triangle
The hypotenuse of a 
It is impossible to tell from the information given.
In a 
Example Question #211 : Right Triangles
Example Question #401 : Triangles
Example Question #1392 : Basic Geometry
What is the area of a right triangle with a height of 5 inches and a base of 3 inches?
To find the area of a triangle, multiply the base by the height, then divide by 2.
Example Question #1391 : Plane Geometry
Find the area of ONE of the triangles formed by the diagonal.
To find the area of a right triangle, use the formula 
Example Question #443 : Geometry
A right triangle has a total perimeter of 12, and the length of its hypotenuse is 5. What is the area of this triangle?
3
12
10
6
15
6
The area of a triangle is denoted by the equation 1/2 b x h.
b stands for the length of the base, and h stands for the height.
Here we are told that the perimeter (total length of all three sides) is 12, and the hypotenuse (the side that is neither the height nor the base) is 5 units long.
So, 12-5 = 7 for the total perimeter of the base and height.
7 does not divide cleanly by two, but it does break down into 3 and 4,
and 1/2 (3x4) yields 6.
Another way to solve this would be if you recall your rules for right triangles, one of the very basic ones is the 3,4,5 triangle, which is exactly what we have here
Example Question #521 : Geometry
The ratio for the side lengths of a right triangle is 3:4:5. If the perimeter is 48, what is the area of the triangle?
240
48
50
108
96
96
We can model the side lengths of the triangle as 3x, 4x, and 5x. We know that perimeter is 3x+4x+5x=48, which implies that x=4. This tells us that the legs of the right triangle are 3x=12 and 4x=16, therefore the area is A=1/2 bh=(1/2)(12)(16)=96.
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