Option B:
Solution:
Given sound level = 120 decibel
To find the intensity of a fire alarm:
where 
Step 1: First divide the decibel level by 10.
120 ÷ 10 = 12
Step 2: Use that value in the exponent of the ratio with base 10.
Step 3: Use that power of twelve to find the intensity in Watts per square meter.
Now, do the cross multiplication,
Option B is the correct answer.
Hence .
The two lines are tangent to the circle at points that are 180 degrees apart.
Well, first let's identify which answers are incorrect, then it will be easier to figure out which are correct.
A. Equilateral: An equilateral triangle is a triangle with 3 equal sides. Since there are 180 degrees in a triangle, an equilateral triangle would have three sides of 60 degrees, and none of 45 degrees. Answer? Incorrect.
B. Isosceles: An isosceles triangle has two sides that are equal. 45 and 45 are equal, therefore, this answer is: Correct!
C. Scalene: A scalene triangle has three unequal sides, therefore, this answer is incorrect.
D. Obtuse: An obtuse triangle has one angle that is more than 90 degrees, therefore, since 45 and 45 equal 90 already, this answer is: incorrect.
E. Right: A right triangle has one right angle (angle that equals 90 degrees) since 45 + 45 = 90, and 90 + 90 = 180, this answer is: Correct!
F. Equiangular: This last choice is practically the same as the first, therefore the answer is: incorrect.
The two correct answers are: B Isosceles, and E Right!
