#### Solved Examples and Worksheet for Identifying and Describing Right Triangles

Q1A triangle has the three angles measuring 90°, 40° and 50°. Which of the following is the best suitable name for that triangle?
A. scalene triangle
B. isosceles triangle
C. right triangle
D. equilateral triangle

Step: 1
A triangle in which one of the angles measures 90° is called a right triangle.
Step: 2
Among the angle measures, one is 90°.
Step: 3
So, a right triangle would be formed with the measures of angles.
Correct Answer is :   right triangle
Q2Identify the figure with a right angle. A. Figure 2
B. Figure 4
C. Figure 3
D. Figure 1

Step: 1
A right angle is an angle whose measure is equal to 90°.
Step: 2
So, among the figures, Figure 4 represents a right angle.
Correct Answer is :   Figure 4
Q3Identify the figure that is not a right triangle. A. Figure 4
B. Figure 1
C. Figure 2
D. Figure 3

Step: 1
A right triangle has one 90° internal angle (a right angle).
Step: 2
One of the angles in all the figures measures 90° except in Figure 4.
Step: 3
Therefore, Figure 4 is not a right triangle.
Correct Answer is :   Figure 4
Q4Which of the given measures could be the measures of the angles of a right triangle?
A. 90°, 75°, 15°
B. 40°, 80°, 60°
C. 120°, 30°, 30°

Step: 1
A right triangle has one 90° internal angle (a right angle).
Step: 2
Among the choices, 90°, 75° and 15° can be the angles of a right triangle.
Correct Answer is :   90°, 75°, 15°
Q5Which figures has an angle that appears to be a right angle? A. Figure 2
B. Figure 3
C. Figure 1

Step: 1
Figure 1 has an angle more than 90°. So, that appears to be an obtuse angle.
Step: 2
Figure 2 has an angle 90°. It is a right angle.
Step: 3
Figure 3 has an angle less than 90°. So, that appears to be an acute angle.
Step: 4
So, Figure 2 has an angle that appears to be a right angle.
Correct Answer is :   Figure 2
Q6Which of the given measures could be the measures of the angles of a right triangle?

A. 120°, 30°, 30°
B. 90°, 35°, 55°
C. 40°, 80°, 60°

Step: 1
A right triangle has one 90° internal angle (a right angle).
Step: 2
Among the choices, 90°, 35° and 55° can be the angles of a right triangle.
Correct Answer is :   90°, 35°, 55°
Q7Identify the type of the triangle. A. isosceles triangle
B. scalene triangle
C. right triangle
D. equilateral triangle

Step: 1
From the figure, A is 90°.
Step: 2
A right triangle is a triangle with a right angle.
Step: 3
The triangle is a right triangle.
Correct Answer is :   right triangle
Q8Identify the figure that is not a right triangle. A. Figure 2
B. Figure 1
C. Figure 3

Step: 1
An angle which measures 90° is called a right angle.
Step: 2
A triangle which measures 90° is called a right angle triangle.
Step: 3
Amongst the figures, Figure 1 and 3 are right triangles and Figure 2 is not a right triangle.
Correct Answer is :   Figure 2
Q9Is it a right triangle? A. Yes
B. No

Step: 1
A right triangle should have one right angle that is 90°.
Step: 2
The given figure does not have 90°.
Step: 3
So, the given figure is not a right triangle.
Q10How many right triangles are there in the following figure? A. 2
B. 8
C. 6
D. 1

Step: 1
A right triangle is a triangle with an angle of 90°.
Step: 2
So, from the given figure, there are two right triangles.