Basic Geometry : Triangles

Study concepts, example questions & explanations for Basic Geometry

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Example Questions

Example Question #81 : How To Find The Area Of A Right Triangle

The diameter of the circle is , find the area of the shaded region.

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Possible Answers:

Correct answer:

Explanation:

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To find the area of the shaded region, we will first need to find the area of the right triangle and the area of the circle.

Recall how to find the area of a circle:

Now, recall how to find the length of the radius from the length of the diameter.

Substitute in the given diameter to find the radius.

Now, substitute in the radius to find the area of the circle.

Next, recall how to find the area of a right triangle.

Substitute in the given base and height to find the area.

We can now find the area of the shaded region:

Solve and round to two decimal places.

 

Example Question #82 : How To Find The Area Of A Right Triangle

The diameter of the circle is , find the area of the shaded region.

11

Possible Answers:

Correct answer:

Explanation:

13

To find the area of the shaded region, we will first need to find the area of the right triangle and the area of the circle.

Recall how to find the area of a circle:

Now, recall how to find the length of the radius from the length of the diameter.

Substitute in the given diameter to find the radius.

Now, substitute in the radius to find the area of the circle.

Next, recall how to find the area of a right triangle.

Substitute in the given base and height to find the area.

We can now find the area of the shaded region:

Solve and round to two decimal places.

 

Example Question #84 : How To Find The Area Of A Right Triangle

The diameter of the circle is , find the area of the shaded region.

12

Possible Answers:

Correct answer:

Explanation:

13

To find the area of the shaded region, we will first need to find the area of the right triangle and the area of the circle.

Recall how to find the area of a circle:

Now, recall how to find the length of the radius from the length of the diameter.

Substitute in the given diameter to find the radius.

Now, substitute in the radius to find the area of the circle.

Next, recall how to find the area of a right triangle.

Substitute in the given base and height to find the area.

We can now find the area of the shaded region:

Solve and round to two decimal places.

 

Example Question #481 : Triangles

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

Possible Answers:

None of these.

Correct answer:

Explanation:

The area of a right triangle can be found by .

Example Question #86 : How To Find The Area Of A Right Triangle

Prblem 6 basic geometry

 

Triangle ABC has the given side lengths. Find the area of triangle ABC.

Possible Answers:

Correct answer:

Explanation:

Imagine a right triangle as a square cut in half at a diagonal angle.

When figuring out the area, you figure it out the same way as finding the area of a square, but after multiplying length x widthdivide the answer by 2.

Example Question #87 : How To Find The Area Of A Right Triangle

Find the area, ,  of a right triangle  whose sides are .

Possible Answers:

Correct answer:

Explanation:

The formula for the area of a right triangle is 

.

Plugging in the values given, 

.

Example Question #84 : How To Find The Area Of A Right Triangle

Shape area right triangle

In the right triangle shown here,  and . What is its area in square units?

Possible Answers:

Correct answer:

Explanation:

The area  of a right triangle is given by , where  represents the length of the triangle's base and  represents the length of the triangle's height. The base  and the height  of the triangle given in the problem are  and  units long, respectively. Hence, the area  of the triangle can be calculated as follows:

.

Hence, the area of a right triangle with base length  units and height  units is  square units.

Example Question #1 : How To Find If Right Triangles Are Congruent

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Are the two right triangles congruent?

Possible Answers:

Yes, by AAA

 

Yes, by HL

 

Yes, by AAS

 

Yes, by AAA

 

No, they are not congruent

 

Correct answer:

Yes, by HL

 

Explanation:

Right triangles are congruent if both the hypotenuse and one leg are the same length. These triangles are congruent by HL, or hypotenuse-leg.

Example Question #1 : How To Find If Right Triangles Are Congruent

Which of the following is not sufficient to show that two right triangles are congruent?

Possible Answers:

All the sides are congruent.

All the angles are congruent.

Both legs are congruent.

The hypotenuse and one leg are congruent.

Correct answer:

All the angles are congruent.

Explanation:

Two right triangles can have all the same angles and not be congruent, merely scaled larger or smaller. If all the side lengths are multiplied by the same number, the angles will remain unchanged, but the triangles will not be congruent.

Example Question #1 : How To Find If Right Triangles Are Congruent

Which of the following pieces of information would not allow the conclusion that 

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Possible Answers:

 bisects 

Correct answer:

Explanation:

To determine the answer choice that does not lead to congruence, we should simply use process of elimination.

If , then subtracting tells us that .; therefore . Given the fact that reflexively  and that both  and  are both right angles and thus congruent, we can establish congruence by way of Side-Angle-Side.

Similarly, if , then , and given the other information we determined with our last choice, we can establish conguence by way of Hypotenuse-Leg.

If , given what we already know we can establish congruence by Angle-Angle-Side

Finally, if  is an angle bisector, then our two halves are congruent. . Given what we know, we can establish congruence by Angle-Side-Angle

The only remaining choice is the case where . This does not tell us how the two parts of this angle are related, we lack enough information for congruence.

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