Virginia SOL Math / Grade 6 / Measurement & Geometry

6.MG.2

Area & Perimeter of Triangles & Parallelograms

What you'll learn

  • Find the area and perimeter of triangles
  • Find the area and perimeter of parallelograms
  • Solve problems in context involving these figures

Words to know

Base —
a side used as the bottom for measuring area
Height —
the perpendicular distance from the base to the top
Parallelogram —
a quadrilateral with two pairs of parallel sides
Perimeter —
the distance around a shape
Perpendicular —
meeting at a right angle

Why it matters Roofs, flags, garden plots, and tiles are often triangles or parallelograms, so we need their area and border length.

Worked examples

Model ItI do

Find the area of a triangle with base 8 cm and height 5 cm.

Area of a triangle equals one half times base times height: 1/2 times 8 times 5. First 8 times 5 = 40, then half of 40 = 20 square centimeters.

Try It TogetherWe do

Find the area of a parallelogram with base 6 in and height 4 in.

Area of a parallelogram equals base times height: 6 times 4 = 24 square inches.

Now YouYou do

Find the area of a triangle with base 10 m and height 6 m.

Use one half times base times height. Check your answer in the back of this chapter.

Practice

Mastered 0 of 11

Warm-up

Ease in with the basics.

  1. 1.Find the area of a triangle with base 6 cm and height 4 cm.

  2. 2.Find the area of a parallelogram with base 5 in and height 3 in.

  3. 3.Find the perimeter of a triangle with sides 3 cm, 4 cm, and 5 cm.

On Level

The core Quick Check from the book.

  1. 1.Find the area of a triangle with base 4 cm and height 9 cm.

  2. 2.Find the area of a parallelogram with base 7 in and height 3 in.

  3. 3.Find the perimeter of a triangle with sides 5 cm, 6 cm, and 7 cm.

  4. 4.A parallelogram has a base of 12 ft and a height of 5 ft. What is its area?

  5. 5.Find the area of a triangle with base 6 m and height 6 m.

Challenge

Stretch your thinking.

  1. 1.A triangle has an area of 24 square cm and a base of 8 cm. What is its height?

  2. 2.Find the area of a parallelogram with base 9 m and height 7 m.

  3. 3.A triangular flag has a base of 10 in and a height of 12 in. What is its area?