Answer:
The volume of the triangular prism is 
Step-by-step explanation:
we know that
The volume of the triangular prism is equal to

where
B is the area of the triangular face
L is the length of the prism
step 1
Find the area of the triangular face
The area of a triangle is equal to

we have

substitute

step 2
Find the volume
we have


substitute in the formula of volume


Complementary angles ⇒ the angles add up to 90°
∠A and ∠B are complementary ⇒ ∠A + ∠B = 90°
∠A + ∠B = 90°
Plug in the values for ∠A and ∠B:
(3x - 8) + (5x + 10) = 90
Open the brackets:
3x - 8 + 5x + 10 = 90
Combine like terms:
8x + 2 = 90
Subtract 2 from both sides:
8x = 88
Divide both sides by 8:
x = 11
Answer: x = 11
3)The original rational number was 17/12.
4)The age of Ruby and Reshma are 20 and 28 years respectively.
Explanation:
3)Let the numerator be x.
So denominator will be (x - 5)
If we add 5 to numberator then it will be (x + 5)
New number is (x + 5)/(x - 5)=11/6
Solve for X by cross multiplying
6(x + 5)=11(x - 5)
6x + 30=11x - 55
5x=85
x=17
So original rational number was 17/12.
4)The ages of Ruby and Reshma are in the ratio 5:7
So, let the present ages of Ruby and Reshma be 5x and 7x respectively.
Also, it is given that four years from now the ratio of their ages will be 3:4
So, the equation - 5x + 4 / 7x + 3 = 3/4
⇒4(5x+4)=3(7x+4)
⇒20x+16=21x+12
⇒21x−20x=16−12
⇒x=4
⇒5x=20 and 7x=28
The age of Ruby and Reshma are 20 and 28 years respectively.
All you have to do is add those two numbers given and subtract by 180. all of the angles shall add up to 180 if not then you dic something wrong