body{margin:0;} noscript{z-index: 10000; position: fixed; display: block; height: 100%; width: 100%; background: #fff;} noscript .fa{font-size: 40px; display:block; color: #daa520;} noscript div{margin-top: 6%; padding-left: 20px; padding-right: 20px; text-align: center;} ! You must have JavaScript enabled to use this site.

Big Ideas Math: Modeling Real Life, Grade 6

BI

Big Ideas Math: Modeling Real Life, Grade 6 View details

2. Areas of Triangles

Continue to next subchapter

Exercise 10 Page 293

The area of a triangle is half the product of its base and its height.

3mi

Practice makes perfect

We want to find the length of the height h of the given triangle. From the figure, we know that the base of the triangle is 4 13 miles long. We are also told that the area is 6 12 square miles. Let's see the diagram!

The area of a triangle is found by taking half of the product of its base and its height. A=1/2bh We can substitute A= 6 12 and b= 4 13 into this formula and solve for h, the height of the triangle. Let's do it!

A=1/2bh

A= 6 12, b= 4 13

6 12=1/2( 4 13)h

▼

Solve for h

a bc=a* c+b/c

6*2+1/2=1/2(4* 3+1/3)h

Multiply

12+1/2=1/2(12+1/3)h

Add terms

13/2=1/2(13/3)h

Multiply fractions

13/2=1* 13/2* 3h

Multiply

13/2=13/6h

LHS * 6=RHS* 6

6* 13/2=6* 13/6 h

DenomMultFracToNumber

6 * a/6= a

6* 13/2=13* h

MoveLeftFacToNum

a*b/c= a* b/c

6* 13/2=13 * h

Multiply

78/2=13* h

Calculate quotient

39=13 * h

.LHS /13.=.RHS /13.

39/13=13 * h/13

Calculate quotient

3=h

Rearrange equation

h=3

The height of the triangle is 3 miles.

Subchapter links

Try It p.292-293

Self-Assessment for Concepts & Skills p.293

Self-Assessment for Problem Solving p.294

Review & Refresh p.295