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!
Tan30 = b/8
b=8tan30 (first choice)
