All About Triangles

The triangles shown are similar. Which side corresponds with side BC?

• AB

• DE

• EF

• CA

The triangles shown are similar. What is the scale factor from ABC to DEF?

• 2

• 3

• 4

• 5

The triangles shown are similar. Find the length of side EF.

• 3

• 12

• 15

• 18

All the angles in a triangle

add up to ....

• 90 degrees

• 180 degrees

• 360 degrees

• It depends on the triangle

A ​ (a)   triangle has ​ (b)   right triangle,

• right

• one

• obtuse

• scalene

• two

• three

• acute

Find the missing angle in the triangle.

Can angles measuring 78^o, 30^o, and 82^o make a triangle?

• Yes

• No

If two side lengths of a triangle are 30 cm and 50 cm, what is a possible length of the third side?

• 70 cm

• 80 cm

• 100 cm

A triangle with all 3 angles measuring less than 90^o is called a(n) ...

• Acute Triangle

• Right Triangle

• Obtuse Triangle

Can the side lengths of 3 ft, 7 ft, and 9 ft create a triangle? Explain.

• No, the shape won't close.

• Yes, the two shorter sides add up to be larger than the third side.

• There is not enough information.