Area of Triangle Practice Problems - Scalene, Right & Obtuse

Master triangle area calculations with step-by-step practice problems covering scalene, right, and obtuse triangles using base-height formulas and real examples.

📚Master Triangle Area Calculations Through Interactive Practice
  • Calculate area of scalene triangles using base and height measurements
  • Apply the right triangle area formula with perpendicular legs
  • Solve obtuse triangle problems with external height projections
  • Identify corresponding base-height pairs for accurate calculations
  • Practice with real measurements and step-by-step solutions
  • Master the fundamental Area = (base × height) ÷ 2 formula

Understanding Area of a Scalene Triangle

Complete explanation with examples

Area of a scalene triangle

Formula to calculate the area of a scalene triangle:

B1  - Area of the scalene triangle

Detailed explanation

Practice Area of a Scalene Triangle

Test your knowledge with 27 quizzes

Calculate the area of the triangle using the data in the figure below.

444777AAABBBCCC8.06

Examples with solutions for Area of a Scalene Triangle

Step-by-step solutions included
Exercise #1

Calculate the area of the right triangle below:

101010666888AAACCCBBB

Step-by-Step Solution

Due to the fact that AB is perpendicular to BC and forms a 90-degree angle,

it can be argued that AB is the height of the triangle.

Hence we can calculate the area as follows:

AB×BC2=8×62=482=24 \frac{AB\times BC}{2}=\frac{8\times6}{2}=\frac{48}{2}=24

Answer:

24 cm²

Video Solution
Exercise #2

Calculate the area of the triangle ABC using the data in the figure.

121212888999AAABBBCCCDDD

Step-by-Step Solution

First, let's remember the formula for the area of a triangle:

(the side * the height that descends to the side) /2

 

In the question, we have three pieces of data, but one of them is redundant!

We only have one height, the line that forms a 90-degree angle - AD,

The side to which the height descends is CB,

Therefore, we can use them in our calculation:

CB×AD2 \frac{CB\times AD}{2}

8×92=722=36 \frac{8\times9}{2}=\frac{72}{2}=36

Answer:

36 cm²

Video Solution
Exercise #3

What is the area of the triangle in the drawing?

5557778.68.68.6

Step-by-Step Solution

First, we will identify the data points we need to be able to find the area of the triangle.

the formula for the area of the triangle: height*opposite side / 2

Since it is a right triangle, we know that the straight sides are actually also the heights between each other, that is, the side that measures 5 and the side that measures 7.

We multiply the legs and divide by 2

5×72=352=17.5 \frac{5\times7}{2}=\frac{35}{2}=17.5

Answer:

17.5

Video Solution
Exercise #4

Calculate the area of the following triangle:

444555AAABBBCCCEEE

Step-by-Step Solution

The formula for calculating the area of a triangle is:

(the side * the height from the side down to the base) /2

That is:

BC×AE2 \frac{BC\times AE}{2}

We insert the existing data as shown below:

4×52=202=10 \frac{4\times5}{2}=\frac{20}{2}=10

Answer:

10

Video Solution
Exercise #5

Calculate the area of the following triangle:

666777AAABBBCCCEEE

Step-by-Step Solution

The formula for the area of a triangle is

A=hbase2 A = \frac{h\cdot base}{2}

Let's insert the available data into the formula:

(7*6)/2 =

42/2 =

21

Answer:

21

Video Solution

Frequently Asked Questions

What is the formula for calculating the area of any triangle?

+
The universal triangle area formula is Area = (base × height) ÷ 2. The key is ensuring the height is perpendicular to the chosen base, forming a 90° angle.

How do you find the area of a scalene triangle?

+
For scalene triangles, use Area = (base × height) ÷ 2. Identify any side as the base, then find the perpendicular height to that base. Multiply base by height, then divide by 2.

What makes calculating right triangle area easier?

+
In right triangles, the two perpendicular sides (legs) can serve as base and height directly. Simply multiply the two legs and divide by 2: Area = (leg₁ × leg₂) ÷ 2.

How do you calculate obtuse triangle area when height is outside?

+
When the height falls outside an obtuse triangle: 1) Use the actual triangle side length (not the extended line), 2) Use the given perpendicular height, 3) Apply the standard formula Area = (base × height) ÷ 2.

What are common mistakes when calculating triangle area?

+
Common errors include: using non-corresponding base-height pairs, measuring slanted sides instead of perpendicular height, forgetting to divide by 2, and using extended lines instead of actual triangle sides in obtuse triangles.

Can you use any side as the base in triangle area calculations?

+
Yes, any side can serve as the base. However, you must use the height that is perpendicular to your chosen base. Different base-height combinations will give the same area result.

What units should triangle area answers include?

+
Triangle area is always expressed in square units (cm², m², in², etc.). If the measurements are in centimeters, the area will be in square centimeters (cm²).

How do you identify the correct height for each triangle type?

+
For right triangles: use the two perpendicular sides. For acute triangles: height is inside the triangle. For obtuse triangles: height may extend outside, but always forms a 90° angle with the base when extended.

More Area of a Scalene Triangle Questions

Continue Your Math Journey

Practice by Question Type