B. All rectangles are parallelograms! And C. All equilateral triangles are isosceles! :-)
Answer:

General Formulas and Concepts:
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
<u>Algebra I</u>
<u>Algebra II</u>
- Distance Formula:

Step-by-step explanation:
<u>Step 1: Define</u>
<em>Identify</em>
Point (21, 13)
Point (3, 13)
<u>Step 2: Find distance </u><em><u>d</u></em>
Simply plug in the 2 coordinates into the distance formula to find distance <em>d</em>
- Substitute in points [Distance Formula]:

- [√Radical] (Parenthesis) Subtract:

- [√Radical] Evaluate exponents:

- [√Radical] Add:

- [√Radical] Evaluate:

Answer:
░░░░░▐▀█▀▌░░░░▀█▄░░░
░░░░░▐█▄█▌░░░░░░▀█▄░░
░░░░░░▀▄▀░░░▄▄▄▄▄▀▀░░
░░░░▄▄▄██▀▀▀▀░░░░░░░
░░░█▀▄▄▄█░▀▀░░
░░░▌░▄▄▄▐▌▀▀▀░░ This is Bob
▄░▐░░░▄▄░█░▀▀ ░░
▀█▌░░░▄░▀█▀░▀ ░░ Copy And Paste Him onto all of ur brainly answers
░░░░░░░▄▄▐▌▄▄░░░ So, He Can Take
░░░░░░░▀███▀█░▄░░ Over brainly
░░░░░░▐▌▀▄▀▄▀▐▄░░
░░░░░░▐▀░░░░░░▐▌░░
░░░░░░█░░░░░░░░█░
do it or he will hunt you down and kill u (lets destroy the moderators!!!!!!!!)
we are slowing them down already! good work soilders!
JOIN THE BOB GANG!!!!!!!!!
Step-by-step explanation:
B = 3h . . . . . . . .given by the problem statement
A = (1/2)bh . . . . formula for the area of a triangle
486 cm² = (1/2)*(3h)*h . . . substitute given information
(2/3)*486 cm² = h² . . . . . .multiply by 2/3
√324 cm = h . . . . . . . . . . . . . .take the square root
The height is 18 cm.
The base is 3*18 = 54 cm.