1. My sweet, beautiful Sabrina
Got ID?
T3.1a To find the Area of a Triangle given two sides and the angle between.
What does this remind you of from Geometry?
My sweet, beautiful Sabrina

2. LESSON: To find the area of any triangle, given two sides and the angle between.C a b c *
Generalize the formula: The area is equal to ½ of the product of any two sides and the sine of the angle between them: * * 2

3. Two sides of a triangle measure 5 cm and 8 cm
Two sides of a triangle measure 5 cm and 8 cm. If the angle between them is 30°, what is the area of the triangle?
8 cm
30°
5 cm
The area is 10 cm2.

4. TRY: If two sides of a triangle measure 36 ft and 60 ft while the area is 864 sq. ft, what is the angle between them? (1 dec. pl.)
60 ft ?
36 ft
The angle is 53.1°.

5. Find the area of a regular octagon inscribed in a circle of radius 15 cm (to 1 dec. pl.) (Hint: first draw it!)
15 cm
15 cm
45°
K = … (last answer
in calculator)
Total Area = ( …) * (8)
The total area is cm2.

6. Active Learning Assignment
(Answers)
P. 342: #7 (158)
#9 (30°)
#10 (30°)
#12 (192 cm2)
WOW:
Learn to show cheerfulness and enthusiasm to others, even if you don’t’ feel like it.