Area of Triangles

Area of Triangles

How can you use the formula for the area of a parallelogram to find the area of a triangle?

USE YOUR WHITEBOARD TO WORK OUT THE PROBLEMS

Hotspot

click or touch the BASE of the triangle

Hotspot

click or touch the HEIGHT of the triangle

Hotspot

click any measurements that are DISTRACTORS and will not be used to calculate area

Multiple Select

What's the formula for the area of a triangle? (You may have more than one answer, click on all that apply)

• $$a=\frac{1}{2}bh$$

• $$a=b\cdot h$$

• $$a=\frac{b\cdot h}{2}$$

• $$a=b-h$$

Fill in the Blanks

find the area of this triangle.

Use the formula: A= ½(b)(h)

Write the number only, not the units

Fill in the Blanks

find the area of this triangle.

Use your formula: A= ½ (b) (h)

write the number answer only

Multiple Choice

Which dimension is missing?

• height

• base

Fill in the Blanks

Find the missing dimension.

Use the formula: A = ½ (b) (h)

Multiple Choice

Which dimension is missing?

• height

• base

Multiple Choice

Find the missing dimension.

• $$5\ yds$$

• $$4\ yds$$

• $$18\ yds$$

• $$12\ yds$$

Multiple Choice

What is the area of this triangle?

• 216 square cm

• 200 square cm

• 108 square cm

• 180 square cm

Fill in the Blanks

Poll

How do you feel about finding the area of a triangle?

• Great!

• So-So

• Confused

Fill in the Blanks

Find the area of this triangle.

Write the numerical answer only

Multiple Choice

Find the area of the triangle.

• 20 cm²

• 56 cm²

• 28 cm²

• 27 cm²

Multiple Choice

A triangle with a height of 20 cm and a base of 9 cm has an area of what?

• 90 cm squared
• 29 cm squared
• 180 cm squared
• 29 mm squared

Multiple Choice

Find the area of a triangle with:
base: 14 cm
height: 23 cm

• 161 cm²
• 161 cm³
• 322 cm²
• 322 cm³

Multiple Choice

Find the area:

• 40 yd
• 40 yd²
• 80 yd²
• 18 yd²

Multiple Choice

What is the area?

• 12 cm²
• 14
• 14 cm²
• 24 cm²

Multiple Choice

Area of triangle?

• 17 units²
• 20 units²
• 10 units²
• 16 units²

Match

Match the following

• b

• A

• h

• =

Base

Area

Height

equals

• Base

• Area

• Height

• equals

Multiple Choice

Which expression below will find the Area of this Triangle?

• $$\frac{\left(12\ \times13\right)}{2}$$

• $$\frac{\left(12\ +13\right)}{2}$$

• $$\frac{\left(13\ -\ 12\right)}{2}$$

• $$12\times13$$