We continue our discussion on how to find the area of a triangle. In the **previous post**, we have learned where the formula for the area of a triangle came from. We have studied that a triangle with area , base and height is

We continue our discussion with the third example in this series.

**Example 3**

What is the base of a height 7 and area 8.75 square centimeters?

*Solution*

Multiplying both sides by 2, we have

.

Dividing both sides by 7 gives us

.

Therefore, the height of the triangle is 2.5 cm.

**Example 4**

Two triangles are formed by drawing a diagonal from the opposite corners of a square. If the side length of the square is 8.4 cm, what is the area of each triangle?

*Solution 1*

The area of a triangle is half the **area of the square**, so we can just find the area of a square and divide it by 2. If we let be the area of the square with side , then

.

Now, since the area of the triangle is half the square, we divide 70.56 by 2 which is equal to 35.28.

So the area of the triangle is 35.28 square units.

*Solution 2*

The base and the height of the triangle are equal. So,

.

So the area of the triangle is 35.28 square units.

**Example 5**

What is the area of the shaded part in the figure below if the side of the square is 8 cm?

*Solution*

The area of the shaded part is half the area of the square. Since the area of the square is 8(8) = 64 square centimeters, the area of the shaded part is equal to 32 square units.

Can you find other solutions?

In the next post, we are going to have a quiz on what we have learned so far.