n a right-angled triangle, the lengths of two shorter sides are 3 cm and 4 cm. Can you find the area of thetriangle using both the Pythagorean theorem and Heron's formula? Explain your approach.
Question
n a right-angled triangle, the lengths of two shorter sides are 3 cm and 4 cm. Can you find the area of thetriangle using both the Pythagorean theorem and Heron's formula? Explain your approach.
Solution
Sure, I can help with that.
First, let's find the length of the hypotenuse using the Pythagorean theorem. The theorem states that in a right-angled triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides.
So, if we let c be the hypotenuse, a and b be the other two sides, we have:
c^2 = a^2 + b^2 c^2 = 3^2 + 4^2 c^2 = 9 + 16 c^2 = 25 c = sqrt(25) c = 5 cm
So, the length of the hypotenuse is 5 cm.
Now, let's find the area of the triangle. The area (A) of a right-angled triangle can be found using the formula:
A = 1/2 * base * height A = 1/2 * 3 cm * 4 cm A = 1/2 * 12 cm^2 A = 6 cm^2
So, the area of the triangle is 6 square cm.
Now, let's use Heron's formula. Heron's formula is used to find the area of a triangle when we know the lengths of all three sides. The formula is:
A = sqrt[s(s - a)(s - b)(s - c)]
where s is the semi-perimeter of the triangle, calculated as (a + b + c) / 2.
So, let's calculate s:
s = (3 cm + 4 cm + 5 cm) / 2 s = 12 cm / 2 s = 6 cm
Now, we can find the area:
A = sqrt[6 cm(6 cm - 3 cm)(6 cm - 4 cm)(6 cm - 5 cm)] A = sqrt[6 cm * 3 cm * 2 cm * 1 cm] A = sqrt[36 cm^2] A = 6 cm^2
So, the area of the triangle is also 6 square cm using Heron's formula. This confirms our earlier calculation.
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