What do you mean doubling? You can add 7+7+7 which equals 21.
The formula for density of an object is Density=

First you plug in the information you already know. 163.5=

Now you have to solve for the mass so you multiply 0.492 by 163.5

Lastly, you simplify and you will get 80.44. Hope this helped :)
Answer:

Step-by-step explanation:
We are given the following in the question:

We have to prove:

Proof:

we can write:

Hence, the two triangle are congruent by SAS congruency rule.

The attached image shows the two triangle.
From what i can tell, it would have Three Lines of Reflectional Symmetry due to its three vertices
Answer:
B. False, they could be vertical angles
Step-by-step explanation:
Supplementary just mean when two angles form 180° (a straight line).
So ∠F and ∠G must form a straight line, and ∠G and ∠H must form a a straight line.
I drew the image out below and as you can see, angle F and H forms a vertical angle. A vertical angles is when two lines cross, the opposite angles from each others are called vertical angles.