Geometry and TrigonometryEasy–MediumPerimeter of a right triangle from its legs
Geometry and Trigonometry practice question
The two legs of a right triangle measure 9 centimetres and 12 centimetres. What is the perimeter of the triangle, in centimetres?
Answer: 36
The hypotenuse is √(81 + 144) = √225 = 15. Perimeter: 9 + 12 + 15 = 36.
Common wrong answers
- If you answered 15
- 15 is the hypotenuse alone.
- If you answered 21
- 21 adds only the two legs, leaving out the hypotenuse.
- If you answered 54
- 54 is the AREA (½ × 9 × 12), not the perimeter.
More Geometry and Trigonometry questions
- Easy–Medium
A circle has a radius of 6. What is its area? (Use A = πr².) - Easy–Medium
A right triangle has legs of length 6 and 8. What is the length of the hypotenuse? - Easy–Medium
A circle has a radius of 5. What is its circumference? (Use C = 2πr.) - Easy–Medium
What is the midpoint of the segment joining the points (2, 3) and (8, 11)? - Easy–Medium
What is the measure, in degrees, of angle B? - Easy–Medium
What is the area, in square centimeters, of the trapezoid?
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