Using distribution to find area

How can I find the area of this triangle? How can I find the area of this rectangle?

A = ½ [ (5x + 2)8 ] b = 6x -3h = 4

A = ½ [ (5x + 2)8 ] A = (6x-3)4

A = ½ (40x + 16) a = (6x-3)4A = 20x + 8 a = 24x - 12

8

5x + 2

A = ½ (b × h) A = b × h

4

6x - 3

Let’s do this one together!

1) Write an expression for the area of this triangle

2) Find the area for this rectangle when x = 3

5

3x + 4

Try this one on your own

1) Write and expression for the area of this rectangle.

2) If m = 4, what is the area of this rectangle?6m - 8

4

CHALLENGE!

Write an expression for the PERIMETER of this rectangle

4y - 5

5y + 2Write an expression for perimeter of this triangle:

5x

8x + 8

6x

1. The perimeter is 120cm. Write an equation to find the side length x, then solve.

40in x

15inCan you find the area of the triangle above?

2. A teddy bear was advertised at a discounted price of $45. The bear was marked with a tag indicating $15 off the original price. Write and solve an equation to find the original price of the teddy bear.

3. Your school of 65 students is going on a field trip to the zoo. It costs $18 per train ticket and $29 per zoo admission. How much money will it cost for you all to go?

A baseball player’s batting average is defined as the number of hits divided by the number of times at bat. If a baseball player batted 600 times and had a batting average of 0.75, how many hits did the batter have?

You use an ATM machine to deposit a check for $145.67 into your checking account. Your receipt from the ATM shows a balance of $561.13 after the deposit. What was the balance of your account before the deposit?

Explain why the fraction ½ is part of the formula for the area of a triangle.