Geometry Practice Questions
Common Core (US) · Common Core Math Grade 8 · 123 free MCQs with instant results and detailed explanations.
123
Total
30
Easy
70
Medium
23
Hard
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Sample Questions from Geometry
Here are 10 sample questions. Start a quiz to get randomized questions with scoring.
Q1
Easy
A rectangle has a length of 10 cm and a width of 5 cm. What is its perimeter?
A.
30 cm
B.
50 cm
C.
20 cm
D.
40 cm
Show Answer & Explanation
Correct Answer: A
The perimeter of a rectangle is calculated using the formula P = 2(length + width). Here, P = 2(10 + 5) = 30 cm.
Q2
Easy
If a triangle has sides measuring 6 cm, 8 cm, and 10 cm, what type of triangle is it?
A.
Scalene
B.
Isosceles
C.
Equilateral
D.
Right
Show Answer & Explanation
Correct Answer: D
A triangle with sides 6 cm, 8 cm, and 10 cm forms a right triangle as it satisfies the Pythagorean theorem (6² + 8² = 10²).
Q3
Easy
If a rectangle has a length of 10 cm and a width of 5 cm, what is its area?
A.
15 cm²
B.
50 cm²
C.
25 cm²
D.
30 cm²
Show Answer & Explanation
Correct Answer: B
The area of a rectangle is calculated by multiplying the length and width. Here, 10 cm × 5 cm = 50 cm².
Q4
Medium
A triangle has sides of lengths 7 cm, 24 cm, and 25 cm. Is this triangle a right triangle?
A.
Yes, it is a right triangle.
B.
No, it is not a right triangle.
C.
It can be either right or obtuse.
D.
It can be either right or acute.
Show Answer & Explanation
Correct Answer: A
A triangle is a right triangle if it satisfies the Pythagorean theorem, a² + b² = c². Here, 7² + 24² = 49 + 576 = 625, and 25² = 625, confirming it is a right triangle.
Q5
Medium
What is the area of a trapezoid with bases measuring 10 cm and 14 cm, and a height of 6 cm?
A.
72 cm²
B.
24 cm²
C.
60 cm²
D.
48 cm²
Show Answer & Explanation
Correct Answer: A
The area of a trapezoid is calculated using the formula: Area = (base1 + base2) × height / 2. Here, it is (10 + 14) × 6 / 2 = 72 cm².
Q6
Medium
A circle has a radius of 4 cm. What is the circumference of the circle?
A.
8π cm
B.
12π cm
C.
16π cm
D.
32 cm
Show Answer & Explanation
Correct Answer: A
The circumference of a circle is calculated using the formula C = 2πr. For a radius of 4 cm, C = 2π × 4 = 8π cm.
Q7
Medium
Which statement about similar triangles is TRUE?
A.
They have the same area.
B.
Their corresponding angles are equal.
C.
Their corresponding sides are equal.
D.
They cannot be similar if one triangle is larger than the other.
Show Answer & Explanation
Correct Answer: B
Similar triangles have proportional sides and equal corresponding angles. Therefore, option B is correct as it correctly describes a property of similar triangles.
Q8
Hard
A triangle has angles measuring 45°, 45°, and x°. What is the value of x?
A.
90°
B.
45°
C.
60°
D.
30°
Show Answer & Explanation
Correct Answer: A
The sum of angles in any triangle is always 180°. In this case, 45° + 45° + x° = 180°. Therefore, x° = 180° - 90° = 90°.
Q9
Hard
A triangle has sides of lengths 7 cm, 24 cm, and 25 cm. What is the area of the triangle?
A.
84 cm²
B.
168 cm²
C.
126 cm²
D.
120 cm²
Show Answer & Explanation
Correct Answer: A
Using Heron's formula, the semi-perimeter (s) is (7 + 24 + 25) / 2 = 28 cm. The area A is √(s(s-a)(s-b)(s-c)) = √(28(28-7)(28-24)(28-25)) = √(28*21*4*3) = √(2352) = 84 cm².
Q10
Hard
A rectangular prism has a length of 10 cm, a width of 6 cm, and a height of h cm. If the volume of the prism is 360 cm³, what is the value of h?
A.
6 cm
B.
5 cm
C.
4 cm
D.
7 cm
Show Answer & Explanation
Correct Answer: A
The volume V of a rectangular prism is given by V = length × width × height. Here, 360 = 10 × 6 × h, which simplifies to h = 360 / 60 = 6 cm.
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Geometry — Common Core (US) Common Core Math Grade 8 Practice Questions Online
This page contains 123 practice MCQs for the chapter Geometry in Common Core (US) Common Core Math Grade 8. The questions are organized by difficulty — 30 easy, 70 medium, 23 hard — so you can choose the right level for your preparation.
Every question includes a detailed explanation to help you understand the concept, not just memorize answers. Take a timed quiz to simulate exam conditions, or practice at your own pace with no time limit.