Geometry & Measurement Flashcards
6 cards from real AMC 8 practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Geometry & Measurement flashcards as text
A square is inscribed in a circle of radius 5. What is the area of the square?
Answer: 50
The diagonal of the inscribed square equals the diameter (10), so s√2 = 10, giving s = 5√2 and area = s² = 50.
How many lines of symmetry does a regular pentagon have?
Answer: 5
A regular pentagon has 5 lines of symmetry, one through each vertex and the midpoint of the opposite side.
A rectangle's length is three times its width. If the perimeter is 48, what is the area?
Answer: 108
With l = 3w, the perimeter gives 2(3w + w) = 48, so w = 6, l = 18, and area = 108.
In a right triangle, one acute angle is 35°. What is the other acute angle?
Answer: 55°
The two acute angles in a right triangle are complementary, so the other angle = 90° − 35° = 55°.
What is the perimeter of a regular octagon with side length 7?
Answer: 56
A regular octagon has 8 equal sides, so perimeter = 8 × 7 = 56.
A cylinder has radius 3 and height 7. What is its volume? (Use π ≈ 3.14)
Answer: 197.82
Volume = π × r² × h = 3.14 × 9 × 7 = 197.82 cubic units.