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If perimeter of an isoceles `Delta ` is 64 cm and height is 8 cm find area .

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To solve the problem of finding the area of an isosceles triangle with a perimeter of 64 cm and a height of 8 cm, we can follow these steps: ### Step-by-Step Solution: 1. **Understanding the Isosceles Triangle**: - An isosceles triangle has two equal sides. Let's denote the length of the equal sides as \( A \) and the base as \( B \). 2. **Using the Perimeter**: - The perimeter of the triangle is given by the formula: \[ \text{Perimeter} = 2A + B \] - According to the problem, the perimeter is 64 cm: \[ 2A + B = 64 \] 3. **Rearranging the Equation**: - We can rearrange the equation to express \( B \) in terms of \( A \): \[ B = 64 - 2A \] 4. **Understanding the Height**: - The height of the triangle divides the base \( B \) into two equal parts. Therefore, each part is: \[ \frac{B}{2} \] 5. **Using the Pythagorean Theorem**: - In the right triangle formed by the height, we can apply the Pythagorean theorem: \[ A^2 = \left(\frac{B}{2}\right)^2 + \text{Height}^2 \] - Substituting the height (8 cm): \[ A^2 = \left(\frac{B}{2}\right)^2 + 8^2 \] 6. **Substituting for \( B \)**: - Substitute \( B = 64 - 2A \) into the equation: \[ A^2 = \left(\frac{64 - 2A}{2}\right)^2 + 8^2 \] - Simplifying: \[ A^2 = \left(32 - A\right)^2 + 64 \] 7. **Expanding and Rearranging**: - Expanding \( (32 - A)^2 \): \[ A^2 = 1024 - 64A + A^2 + 64 \] - Cancel \( A^2 \) from both sides: \[ 0 = 1088 - 64A \] - Rearranging gives: \[ 64A = 1088 \] - Solving for \( A \): \[ A = \frac{1088}{64} = 17 \] 8. **Finding \( B \)**: - Substitute \( A \) back into the equation for \( B \): \[ B = 64 - 2 \times 17 = 30 \] 9. **Calculating the Area**: - The area \( A \) of the triangle can be calculated using the formula: \[ \text{Area} = \frac{1}{2} \times \text{Base} \times \text{Height} \] - Substituting the values: \[ \text{Area} = \frac{1}{2} \times 30 \times 8 = 120 \text{ cm}^2 \] ### Final Answer: The area of the isosceles triangle is \( 120 \text{ cm}^2 \). ---
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