The document explains how to find the area of different shapes including squares, rectangles, triangles, and circles. It provides the area formulas for each shape and works through examples of calculating area. Practice problems are included at the end for circles, triangles, and rectangles.

1. How to Find … Created by Ryan Massey

4. Some of The “ 2-D ” Area Formula’s 3 6 5 10 2 Circles ½(bh)=A ½(5 x 10) =A ½ (50) = A 25 =A ½ (bh)= A Or Triangle bh = A 6 x 3 =A 18 =A bh = A (and another formula for the Square). Square / Rectangle ~~~~~~Example~~~~~~ Formula(s) Shape(s)

7. Practice Problems 5 7.5 A 3.95 B 19 14 ½ C

8. Problem A 5 7.5 Write out our formula.. (bh) = A Fill in the numbers that we know.. (5 x 7.5) = A

9. Problem A (cont.) 5 7.5 Multiply the numbers in the Parenthesis… (5 x 7.5) = A 37.5 = A

10. Problem B 3.95 Write out our formula.. (s) 2 = A Fill in the numbers that we know.. (3.95) 2 = A (3.95) 2 = A Square the number (3.95) 2 = 15.60 = A

11. Problem C 19 14 ½ Write out our formula.. (bh) = A Fill in the numbers that we know.. (19 x 14.5) = A

12. Problem C (cont.) Multiply the numbers in the Parenthesis… (19 x 14.5) = A 275.5 = A 19 14 ½

13. Our Area's are… 5 7.5 37.5 = A A 3.95 (3.95) 2 = 15.60 = A B 275.5 = A 19 14 ½ C

15. Triangles ( cont . ) The BLUE line is The Height of this Triangle. The RED Line is The Base of this Triangle . The GREEN Is the AREA Of this Triangle

16. Practice Problems with Triangles 24 12 10 5 19 4 A B C

17. (suggestions) !!!WAIT!!! Before we move on to see the answers, Go ahead and WORK-OUT the answers, then watch & see how's it done!!! Happy Calculating!

18. Problem A 24 12 A Write out our formula.. ½(bh) = A Fill in the numbers that we know.. ½(12 x 24) = A Click to See the Next set of Steps.

19. Problem A (cont.) 24 12 A Multiply the numbers in the Parenthesis… ½(12 x 24) = A ½ (288) = A Divide our area that we multiplied out by 2 or ½ . ½(288) = A ½(288) = 144

20. Problem B 10 5 B Write out our formula.. ½(bh) = A Fill in the numbers that we know.. ½( 5 x 10) = A Click to See the Next set of Steps.

21. Problem B (cont.) Multiply the numbers in the Parenthesis… ½(5 x 10) = A ½ (50) = A 10 5 B Divide our area that we multiplied out by 2 or ½ . ½(50) = A ½(50) = 25

22. Problem C 19 4 C Write out our formula.. ½(bh) = A Fill in the numbers that we know.. ½(4 x 19) = A

23. Problem C (cont.) 19 4 C Multiply the numbers in the Parenthesis… ½(4 x 19) = A ½ (76) = A Divide our area that we multiplied out by 2 or ½ . ½(76) = A ½(76) = 38

24. So… Our correct answers are.. A= 25 24 12 A A= 144 10 5 B 19 4 C A = 38

26. Quick Definitions Radius Diameter When the circle chows the Diameter, you still need to 1 st find the radius. And square the radius. ( Or your answer will be WRONG!) H I N T Is double of the radius .( Or ) The line that goes from one side of the circle to the other side, passing through the center of the circle. Diameter (in blue) The line that is ½ of the distance of the Diameter Radius ( or ) radii ( In red>>) Definition Name/ Hint

27. How do I find Area of a Circle? 2 Write out our formula.. Fill in the numbers that we know.. A= (3.14)(2) 2

28. Finding the Area of Circles (cont.) Multiply the Numbers in the Parenthesis Now, it is 6.28 to the 2 nd power. A= (3.14)(2) 2 A= 6.28 2 A= 6.28 2 A= 39.43 2

29. Practice Problems 5 8.5 30 Find the AREA Of the circles A-C a b c

30. Problem a 5 Write out our formula.. Fill in the numbers that we know.. A= (3.14)(5) 2

31. Problem a (cont.) Multiply the Numbers in the Parenthesis Now, it is 15.7 to the 2 nd power. A= (3.14)(5) 2 A= 15.7 2 A= 15.7 2 A= 246.49 5

32. Problem b 30 Write out our formula.. Fill in the numbers that we know.. A= (3.14)( 30 ) 2 We Need to now find The RADIUS of this Circle. 30/2 = 15 << 15 , is now The radii or radius for This problem.

33. Problem b (cont.) Multiply the Numbers in the Parenthesis Now, it is 47.1 to the 2 nd power. A= (3.14)(15) 2 A=47.1 2 A= 47.1 2 A= 2218.41 30

34. Problem c 8.5 Write out our formula.. Fill in the numbers that we know.. A= (3.14)(8.5) 2

35. Problem c (cont.) Multiply the Numbers in the Parenthesis Now, it is 26.69 to the 2 nd power. A= (3.14)(8.5) 2 A= 26.69 2 A= 26.69 2 A= 712.35 8.5

36. So… Our Area’s are… A= 246.49 5 A= 2218.41 30 A= 712.35 8.5