DECA=10, decagon = 10 sides.
since each side is 1.8 long, all 10 sides will be 10*1.8 or 18 units long, so that'd be the perimeter then,
If each week the tank decreased by 3 inches, in 2 weeks it would be 6 in, 3 weeks is 9 in, 4 weeks would be 12 in, and 5 weeks would be 15 in.
Answer:
D) 20.
Step-by-step explanation:
First find the value of x using Pythagoras theorem:
10^2 = x^2 + (2x)^2
5x^2 = 100
x^2 = 20
x = √20
= 2√5.
So the area of triangle
= 1/2 * base * height
= 1/2 * 2x * x
= x^2
= (2√5)^2
= 20.
40.8 ÷ 69.9 = 0.5836909871
58%
