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Triangle area and perimeter calculation worksheet with nine problems.

Worksheet for calculating area and perimeter of triangles with labeled sides and heights, including space for answers and triangle types.

Worksheet for calculating area and perimeter of triangles with labeled sides and heights, including space for answers and triangle types.

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Show Answer Key & Explanations Step-by-step solution for: Geometry Worksheets | Triangle Worksheets | Geometry worksheets ...
I'll solve each triangle problem step by step, calculating the area, perimeter, and identifying the type.

Triangle 1:
- Given: a = 4.27 ft, b = 9.21 ft, c = 9.8 ft, h = 4 ft
- Area = (1/2) × base × height = (1/2) × 9.8 × 4 = 19.6 ft²
- Perimeter = a + b + c = 4.27 + 9.21 + 9.8 = 23.28 ft
- Type: Scalene (all sides different lengths)

Triangle 2:
- Given: a = 7.4 inches, b = 4.8 inches, c = 8.82 inches (right triangle with right angle between a and b)
- Area = (1/2) × 7.4 × 4.8 = 17.76 in²
- Perimeter = 7.4 + 4.8 + 8.82 = 21.02 in
- Type: Right scalene (has right angle, all sides different)

Triangle 3:
- Given: a = 5.71 mm, b = 8.49 mm, c = 8.4 mm, h = 5.4 mm
- Area = (1/2) × 8.4 × 5.4 = 22.68 mm²
- Perimeter = 5.71 + 8.49 + 8.4 = 22.6 mm
- Type: Scalene (all sides different)

Triangle 4:
- Given: s = 5.9 yds (equilateral triangle - all sides equal to s)
- For equilateral triangle, we need height first: h = (√3/2) × s = 0.866 × 5.9 ≈ 5.11 yds
- Area = (1/2) × 5.9 × 5.11 ≈ 15.07 yd²
- Or using formula: Area = (√3/4) × s² = 0.433 × 34.81 ≈ 15.07 yd²
- Perimeter = 3 × 5.9 = 17.7 yds
- Type: Equilateral (all sides equal)

Triangle 5:
- Given: a = 8.6 ft, b = 4.3 ft, c = 9.62 ft (right triangle)
- Area = (1/2) × 8.6 × 4.3 = 18.49 ft²
- Perimeter = 8.6 + 4.3 + 9.62 = 22.52 ft
- Type: Right scalene

Triangle 6:
- Given: a = 4.5 cm, b = 6.4 cm (isosceles triangle with two sides = b)
- Third side = a = 4.5 cm
- Need height: Using Pythagorean theorem, h = (6.4² - 2.25²) = √(40.96 - 5.0625) = √35.8975 ≈ 5.99 cm
- Area = (1/2) × 4.5 × 5.99 ≈ 13.48 cm²
- Perimeter = 4.5 + 6.4 + 6.4 = 17.3 cm
- Type: Isosceles (two sides equal)

Triangle 7:
- Given: a = 6.33 yds, b = 8.16 yds, c = 8.6 yds, h = 5.7 yds
- Area = (1/2) × 8.6 × 5.7 = 24.51 yd²
- Perimeter = 6.33 + 8.16 + 8.6 = 23.09 yds
- Type: Scalene (all sides different)

Triangle 8:
- Given: a = 8.2 cm, b = 5 cm, c = 9.6 cm (right triangle)
- Area = (1/2) × 8.2 × 5 = 20.5 cm²
- Perimeter = 8.2 + 5 + 9.6 = 22.8 cm
- Type: Right scalene

Triangle 9:
- Given: a = 4 inches, b = 6.7 inches (isosceles with two sides = b)
- Third side = a = 4 inches
- Height: h = √(6.7² - 2²) = √(44.89 - 4) = √40.89 ≈ 6.39 inches
- Area = (1/2) × 4 × 6.39 ≈ 12.78 in²
- Perimeter = 4 + 6.7 + 6.7 = 17.4 in
- Type: Isosceles (two sides equal)

Final Answer:

1) Area: 19.6 ft², Perimeter: 23.28 ft, Type: Scalene

2) Area: 17.76 in², Perimeter: 21.02 in, Type: Right scalene

3) Area: 22.68 mm², Perimeter: 22.6 mm, Type: Scalene

4) Area: 15.07 yd², Perimeter: 17.7 yds, Type: Equilateral

5) Area: 18.49 ft², Perimeter: 22.52 ft, Type: Right scalene

6) Area: 13.48 cm², Perimeter: 17.3 cm, Type: Isosceles

7) Area: 24.51 yd², Perimeter: 23.09 yds, Type: Scalene

8) Area: 20.5 cm², Perimeter: 22.8 cm, Type: Right scalene

9) Area: 12.78 in², Perimeter: 17.4 in, Type: Isosceles
Parent Tip: Review the logic above to help your child master the concept of triangle perimeter worksheet.
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