Download presentation

1
**Solve for unknown measures**

EXAMPLE 2 Solve for unknown measures Algebra The base of a triangle is twice its height. The area of the triangle is 36 square inches. Find the base and height. Let h represent the height of the triangle. Then the base is 2h. A = bh 2 1 Write formula. 36 = (2h)(h) 2 1 Substitute 36 for A and 2h for b. 36 = h2 Simplify. 6 = h Find positive square root of each side. The height of the triangle is 6 inches, and the base is = 12 inches. ANSWER

2
EXAMPLE 3 Solve a multi-step problem Painting You need to buy paint so that you can paint the side of a barn. A gallon of paint covers 350 square feet. How many gallons should you buy? SOLUTION You can use a right triangle and a rectangle to approximate the area of the side of the barn.

3
**(338 ) EXAMPLE 3 Solve a multi-step problem STEP 1**

Find the length x of each leg of the triangle. 262 = x2 + x2 Use Pythagorean Theorem. 676 = 2x2 Simplify. 338 = x Solve for the positive value of x. STEP 2 Find the approximate area of the side of the barn. Area = Area of rectangle + Area of triangle = 26(18) + 1 2 (338 ) = 637 ft2

4
**Solve a multi-step problem**

EXAMPLE 3 Solve a multi-step problem STEP 3 Determine how many gallons of paint you need. 637 ft 1.82 gal 350 ft2 1 gal Use unit analysis. Round up so you will have enough paint. You need to buy 2 gallons of paint.

5
**Let the length of the base be x**

GUIDED PRACTICE for Examples 2 and 3 A parallelogram has an area of 153 square inches and a height of 17 inches. What is the length of the base? 4. SOLUTION Let the length of the base be x A = b h Write formula. 153 = x 17 Substitute 153 for A and 17 for h and x for b. x = 9 Simplify. ANSWER Length of the base is 9 in.

6
**Find the length x of each leg of the triangle.**

GUIDED PRACTICE for Examples 2 and 3 WHAT IF? In Example 3, suppose there is a 5 foot by 10 foot rectangular window on the side of the barn. What is the approximate area you need to paint? 5. SOLUTION You can use a right triangle and a rectangle to approximate the area of the side of the barn. STEP 1 Find the length x of each leg of the triangle. 262 = x2 + x2 Use Pythagorean Theorem. 676 = 2x2 Simplify. 338 = x Solve for the positive value of x.

7
**(338 ) GUIDED PRACTICE for Examples 2 and 3 STEP 2**

Find the approximate area of the side of the barn. Area = Area of rectangle + Area of triangle 2 (338 ) = 26(18) + 1 = 637 ft2 STEP 3 Find the area of window. A = l b Write formula. = Substitute. = 50 ft2 Multiply.

8
GUIDED PRACTICE for Examples 2 and 3 Find the approximate area you need to paint. STEP 4 Area of side of barn – Area of window = 637 – 50 = 587 ANSWER You need to paint an approximate area of 587 ft2.

Similar presentations

© 2023 SlidePlayer.com Inc.

All rights reserved.

To make this website work, we log user data and share it with processors. To use this website, you must agree to our Privacy Policy, including cookie policy.

Ads by Google