Triangles Area and Perimeter

Lesson: Perimeter and Area of Triangles

​Math 8

Perimeter of Triangles

• Triangle has 3 sides

• Perimeter = Add up all 3 sides

Multiple Select

Select all of the sides of the triangle.

• 12 cm

• 14 cm

• 16 cm

• 8 cm

Multiple Choice

Find the perimeter.

• 50 cm

• 36 cm

• 38 cm

• 34 cm

Multiple Select

Select all of the sides of the triangle.

• 26 m

• 20 m

• 15 m

• 12 m

Multiple Choice

Find the perimeter.

• 73 m

• 58 m

• 47 m

• 61 m

Area of Triangles

• A triangle is HALF of a rectangle

• Rectangle formula = Length x Width or Base x Height

• Triangle formula = 1/2 * base * height

Area of Triangles

• Base means the bottom of a triangle

• Height must be straight and tall = makes a 90^o angle with the base (perpendicular)

• Triangle formula = 1/2 * base * height

Multiple Choice

What is the BASE?

• 60 yd

• 40 yd

• 75 yd

Multiple Choice

What is the HEIGHT?

• 60 yd

• 40 yd

• 75 yd

Multiple Choice

What is the area?

A = 1/2bh (1/2 x base x height)

• 175 yd

• 2,400 yd²

• 1,500 yd²

• 1200 yd²

Multiple Choice

What is the BASE of the Triangle?

• 14 cm

• 12 cm

• 16 cm

• 8 cm

Multiple Choice

What is the HEIGHT of the triangle?

• 14 cm

• 12 cm

• 16 cm

• 8 cm

Multiple Choice

What is the area?

A = 1/2bh (1/2 x base x height)

• 48 cm²

• 112 cm²

• 56 cm²

• 36 cm

Multiple Choice

What is the BASE of the triangle?

• 20 m

• 26 m

• 15 m

• 12 m

Multiple Choice

What is the HEIGHT of the triangle?

• 20 m

• 26 m

• 15 m

• 12 m

Multiple Choice

What is the area?

A = 1/2bh (1/2 x base x height)

• 240 m²

• 120 m²

• 150 m²

• 300 m²

Multiple Choice

Find the perimeter of this triangle.

• 150 ft
• 100 ft
• 20 ft
• 35 ft

Multiple Choice

Find the area of this triangle.

• 240 ft²
• 56 ft²
• 66 ft²
• 120 ft²

Multiple Choice

Find the perimeter of this triangle.

• 240 ft
• 56 ft
• 66 ft
• 120 ft

Multiple Choice

Find the perimeter of this triangle.

• 12 in

• 22 in

• 18 in

• 24 in

Multiple Choice

Find the area of this triangle.

• 12 in²
• 22 in²
• 18 in²
• 24 in²

Multiple Choice

Find the area of the triangle.

• 25.5 cm sq

• 16.83 cm sq

• 18.51 cm sq

• 15.81 cm sq

Multiple Choice

Find the area of the triangle.

• 42 yd

• 17.1 yd

• 42 yd sq

• 17.1 yd sq