1. Students will find the area of triangles (10-2).
Objective:
Students will find the area of triangles (10-2).

2. Vocabulary Triangle height – the distance from a base to the opposite
vertex.
Triangle base – any one of its
sides.
Area of a triangle – A = ½ bh

3. Steps: Read directions and write problem.
Use the following formula A=1/2bh.
Plug in your #’s.
Multiply.
Divide by 2.
Write final answer.

4. Examples
Find the area of each triangle. 6 10

5. Examples
Find the area of each triangle. 6 10
A = ½ bh

6. Examples Find the area of each triangle. A = ½ bh6 10
A = ½ bh
A = ½ x 10 x replace b with 10 and h with 6

7. Examples Find the area of each triangle. A = ½ bh6 10
A = ½ bh
A = ½ x 10 x replace b with 10 and h with 6
A = 5 x 6

8. Examples Find the area of each triangle. A = ½ bh6 10
A = ½ bh
A = ½ x 10 x replace b with 10 and h with 6
A = 5 x 6
A = The area is 30 units²

9. Examples
Find the area of each triangle.
17cm
28cm

10. Examples
Find the area of each triangle.
17cm
28cm
A = ½ bh

11. Examples Find the area of each triangle. A = ½ bh A = ½ x 28 x 17 17cm

12. Examples Find the area of each triangle. A = ½ bh A = ½ x 28 x 17
17cm
28cm
A = ½ bh
A = ½ x 28 x 17
A = 14 x 17

13. Examples Find the area of each triangle. A = ½ bh A = ½ x 28 x 17
17cm
28cm
A = ½ bh
A = ½ x 28 x 17
A = 14 x 17
A = The area is 238 cm².

14. Examples
Find the area of the Bermuda Triangle. Let the base be the distance from Melbourne to Bermuda (1,150 mi). Then the height will be 756 mi.

15. Find the area of the Bermuda Triangle
Find the area of the Bermuda Triangle. Let the base be the distance from Melbourne to Bermuda (1,150 mi). Then the height will be 750 mi.
A = ½ bh

16. Find the area of the Bermuda Triangle
Find the area of the Bermuda Triangle. Let the base be the distance from Melbourne to Bermuda (1,150 mi). Then the height will be 750 mi.
A = ½ bh
A = ½ x 1,150 x 756

17. Find the area of the Bermuda Triangle
Find the area of the Bermuda Triangle. Let the base be the distance from Melbourne to Bermuda (1,150 mi). Then the height will be 750 mi.
A = ½ bh
A = ½ x 1,150 x 756
A = 575 x 756

18. Find the area of the Bermuda Triangle
Find the area of the Bermuda Triangle. Let the base be the distance from Melbourne to Bermuda (1,150 mi). Then the height will be 750 mi.
A = ½ bh
A = ½ x 1,150 x 756
A = 575 x 756
A = 434,700 The area of the Bermuda Triangle is 434,700 mi².

19. Guided Practice
Find the area of each triangle. 9 6
7mm
10mm
8ft
12ft

20. Guided Practice Find the area of each triangle. A = ½ bh A = ½ x 10x79 6
7mm
10mm
8ft
A = ½ bh
A = ½ x 10x7
A = 5x7
A= 35 mm²
A = ½ bh
A = ½ x 6x9
A = 3x9
A = 27 units²
12ft
A = ½ bh
A= ½ x 12x8
A = 6x8
A = 48 ft²

21. Guided Practice
What is the area of a triangle with a height of 40m and a base of 56.8m?

22. Guided Practice
What is the area of a triangle with a height of 40m and a base of 56.8m?
A = ½ bh
A = ½ x 56.8 x 40
A = 28.4 x 40
A = 1,136m²