Area of Triangles Examples

Find the area of a triangle with a base of 7 ft and a height of 4 ft.

The area of any triangle can be calculated using the formula . Here, we have b = 7 ft and h = 4 ft, so all we need to do is plug in the numbers and solve for A.

A = ½bh
A = ½(7 ft)(4 ft)
A = 14 ft²

Find the area of a triangle with a base of 20 cm and a height that's twice the length of the base.

If the height is twice the length of the base, we know that h = 2b. Since b = 20 cm, we know that h = 2(20 cm) = 40 cm. Now, we can use these values and the area formula to find the area.

A = ½bh
A = ½(20 cm)(40 cm)
A = 400 cm²

Find the area of an equilateral triangle with a side length of 4 yards.

Calculating the height of this triangle wouldn't be too difficult if we rocked the Pythagorean Theorem, but why do that when we have a formula? Let's plug and chug. We know that the area of an equilateral triangle is , so let's just substitute 4 for s.