What is the surface area of this triangular pyramid?
1 answer:
<em>48.25 in^2</em>
Step-by-step explanation:
The formula for the surface area of a pyramid is:
B represents the area of the base, which in this case is a triangle. We will figure out the area of the base first, using the formula for the area of a triangle.
A = 10.75
Now we can plug in 10.75 for B.
The cursive L will be the lateral height, which is 5. Since there are 3 sides on the base we can put that in for the number of base sides, and the base is 5.
48.25 in^2
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Answer: The correct option is (D) SET 4.
Step-by-step explanation: We are to select the correct set of side lengths that will form a right-angled triangle.
To form a right-angled triangle, we must have the following relation:
<em>Perpendicular² + Base² = Hypotenuse².</em>
<em>Hypotenuse is the length of the largest side; perpendicular and base are the two legs of the triangle.</em>
SET 1 : 14 cm, 5 cm, 6 cm.
We have
Therefore,
<em>Perpendicular² + Base² ≠ Hypotenuse².</em>
So, this set will not form a right-angled triangle.
SET 2 : 8 in., 12 in., 20 in.
We have
Therefore,
<em>Perpendicular² + Base² ≠ Hypotenuse².</em>
So, this set will not form a right-angled triangle.
SET 3 : 10 mm, 20 mm, 30 mm.
We have
Therefore,
<em>Perpendicular² + Base² ≠ Hypotenuse².</em>
So, this set will not form a right-angled triangle.
SET 4 : 12 ft, 16 ft, 20 ft.
We have
Therefore,
<em>Perpendicular² + Base² = Hypotenuse².</em>
So, this set will form a right-angled triangle.
Thus, the SET 4 will form a right-angles triangle.
Option (D) is correct.