Triangle Angle and Side Challenges for 4th Graders

A triangle has two angles measuring 45 degrees. What is the measure of the missing angle?

• 60 degrees

• 120 degrees

• 75 degrees

• 90 degrees

In a triangle, one angle measures 60 degrees and the other measures 80 degrees. What is the measure of the third angle?

• 70 degrees

• 50 degrees

• 30 degrees

• 40 degrees

A triangle has sides measuring 5 cm, 12 cm, and a missing side. If the triangle is a right triangle, what is the length of the missing side?

• 9 cm

• 10 cm

• 15 cm

• 13 cm

A triangle has a perimeter of 30 cm. If two sides measure 10 cm and 8 cm, what is the length of the missing side?

• 9 cm

• 14 cm

• 12 cm

• 7 cm

In a triangle, the first angle is twice the second angle, and the third angle is 20 degrees more than the second angle. What are the measures of all three angles?

• First angle: 90 degrees, Second angle: 45 degrees, Third angle: 65 degrees

• First angle: 60 degrees, Second angle: 30 degrees, Third angle: 50 degrees

• First angle: 80 degrees, Second angle: 40 degrees, Third angle: 60 degrees

• First angle: 70 degrees, Second angle: 35 degrees, Third angle: 55 degrees

A triangle has one angle measuring 90 degrees and another measuring 30 degrees. What is the measure of the missing angle?

• 30 degrees

• 90 degrees

• 60 degrees

• 45 degrees

A triangle has sides of lengths 7 cm, 24 cm, and a missing side. If it is a right triangle, what is the length of the missing side?

• 25 cm

• 20 cm

• 30 cm

• 22.9 cm

In a triangle, the first angle is 50 degrees, and the second angle is 30 degrees. What is the measure of the third angle?

• 70 degrees

• 100 degrees

• 90 degrees

• 120 degrees

A triangle has a base of 10 cm and a height of 5 cm. What is the area of the triangle?

• 20 cm²

• 15 cm²

• 25 cm²

• 30 cm²

A triangle has a perimeter of 50 cm. If one side is 15 cm and another side is 20 cm, what is the length of the missing side?

• 15 cm

• 30 cm

• 10 cm

• 25 cm