Using Pythagorean theorem, we can justify our answer.
if c^2 = a^2 + b^2 then triangle is right one,
if c^2 > a^2 + b^2 then triangle is obtuse and
if c^2 < a^2 + b^2 then triangle is acute triangle.
Here a=8, b=11 and c=16
Put these values in the equation
16^2 = 8 ^2 + 11^2
256 = 64 +121
256> 185
So here c^2 > a^2 + b^2 Which means triangle is obtuse triangle.
Answer: Obtuse Triangle
Since $14 is the price after a 30% discount then $14 is 70% of the original price.
$14/70=x/100 (100% would be the original price)
1400=70x or 1400/70 = $20!
You can double check the work by taking 30% off the $20 (10% would be $2, 30% would then be $6) 20-6=14!
There’s no a in the the equation
First term (a) = -15
common difference(d)= -9-(-15)
= -9+15=6
So,
12th term(a12)= a +(n-1)d
= -15+(12-1)×6
= -15 + 11×6
= -15+66
= 51
