TODAY IN GEOMETRY…

Review: Pythagorean Theorem and Perimeter

Learning Target: 11.1 You will find areas of triangles and parallelograms.

Independent practice

Ch. 7 Retakes

CH.8 TEST – NEXT WEEK!

REVIEW: The lengths of the hypotenuse and one leg of a right triangle are given. Find the perimeter of the triangle.1. Hypotenuse: 15 in. Leg: 12 in.

2. Hypotenuse: 34 ft. Leg: 16 ft.

12 𝑖𝑛 .

15 𝑖𝑛 .𝑥

16 𝑓𝑡 .

34 𝑓𝑡 .𝑥

9 𝑖𝑛 . Perimeter: Perimeter:

12 𝑓𝑡 .

AREA OF A SQUARE:

𝑠

𝑠

𝐴𝑟𝑒𝑎=𝑠 ∙𝑠=𝑠2

AREA OF A RECTANGLE:

𝑏

h

𝐴𝑟𝑒𝑎=𝑏 ∙ h

EXAMPLE: Find the value of x.

Use Area of a Square Substitute known values

Divide

25𝑐𝑚

𝐴𝑟𝑒𝑎=750𝑐𝑚2𝑥

PRACTICE: Find the value of x.

Use Area of a Rectangle Substitute known values

Divide

AREA OF A PARALLELOGRAM:

𝑏

h

𝐴𝑟𝑒𝑎=𝑏 ∙ h

h

EXAMPLE: Find the area of the given figure.

60 °

20 𝑖𝑛 .

12 𝑖𝑛 .60 °

Special Right Triangle:

12 𝑖𝑛 .

𝑥

𝟔√𝟑 𝒊𝒏 .

PRACTICE: Find the area of the given figure.

8𝑚

20𝑚

Use Area of a Parallelogram Substitute known values

Multiply

AREA OF A TRIANGLE:

𝑏

h

𝐴𝑟𝑒𝑎=12𝑏h

EXAMPLE: Find the perimeter and the area of the right triangle.

10 𝑖𝑛 .

6 𝑖𝑛 .

Find missing leg of right triangle using Pythagorean Theorem:

8 𝑖𝑛 .

PRACTICE: Find the perimeter and the area of the right triangle that has a leg of 20 cm and a hypotenuse of 29 cm.

29𝑐𝑚

20𝑐𝑚

Find missing leg of right triangle using Pythagorean Theorem:

21𝑐𝑚

PRACTICE: Find the perimeter and the area of the given polygon.

Perimeter:

Perimeter:

Pythagorean Thrm:

Perimeter:

PRACTICE: Find the area of the shaded region.

Pythagorean Thrm. to find x:

𝒙 𝒙1

2

Find areas separately, then total!

𝒉=𝟖−𝟓=𝟑𝒉

HOMEWORK #6:

Pg. 723: 3-8, 10, 12, 13, 16, 17, 22, 23, 28

If finished, work on other assignments:

HW #1: Pg. 510: 3-16, 19, 24-26HW #2: Pg. 518: 3-11, 13-15, 23-31HW #3: Pg. 526: 8-14, 19-21, 25-27, 43-47HW #4: Pg. 537: 3, 14, 19-25HW #5: Pg. 546: 3-16, 18-23