Step-by-step explanation:
let the angles be ' 7x, 8x and 5x'
as we know, the sum of all the angles of a triangle is 180 degree, so,
7x + 8x + 5x = 180
20 = 180
x = 180/2
x = 90 degrees
7x = 7 × 90 = 630 degree
8x = 8 × 90 = 720 degrees
5x = 5 × 90 = 540 degrees
therefore, 5x is the smallest degrees
12d-3d= 9d + 2 = 5
Subtract 2 from both sides you get
9d= 3
Divide by 9 by both sides
D= 0.33
The amount of radioactive material that would remain by the 7th hour of decay is 0.12 grams.
<h3>
Exponential function</h3>
An exponential function is in the form:
y = abˣ
where y,x are variables, a is the initial value and b is the multiplicative factor.
Let y represent the amount of substance remaining after x hours. Hence:
a = 9375, at x = 4, y = 15:
15 = 9375(b)⁴
b = 0.2
y = 9375(0.2)ˣ
For the 7th hour, x = 7:
y = 9375(0.2)⁷ = 0.12
The amount of radioactive material that would remain by the 7th hour of decay is 0.12 grams.
Find out more on Exponential function at: brainly.com/question/12940982
Answer: 2
Step-by-step explanation:

It is pi x 11(x2 to get diameter) so it would be 69.08...