Plane geometry (polygons, triangles, angles) — ISEE Upper practice questions
Plane geometry (polygons, triangles, angles) on ISEE Upper Quantitative Reasoning covers rectangles, squares, triangles, and other polygons, including sides, perimeters, areas, and angle relationships. A student has to reason about how a change in length or width affects area, compare a rectangle with a square that shares a perimeter, and apply triangle facts without heavy calculation. Items appear as word problems or quantitative comparisons asking which quantity is larger. Common traps include mixing perimeter with area, treating a percent change in one side as the same change in area, and assuming equal perimeters mean equal areas. Answer choices are four labeled options, often with a cannot-be-determined choice on comparisons.
Section: Quantitative Reasoning 37 questions on the paper
179 practice questions in the app
Sample questions
Question 1
A rectangle's length is decreased by 20%, and its width is increased by 50%. The area of the new rectangle is what percent of the area of the original rectangle?
A70%
B100%
C120%
D130%
Show answer
Answer: C — 120%
The new length is 0.8 of the original and the new width is 1.5 of the original. The area scale factor is 0.8×1.5=1.2, so the new area is 120% of the original.
Question 2
A rectangle has length twice its width. A square has the same perimeter as the rectangle.
Column A
Column B
The area of the rectangle
The area of the square
AThe quantity in Column A is greater
BThe quantity in Column B is greater
CThe two quantities are equal
DThe relationship cannot be determined from the information given
Show answer
Answer: B — The quantity in Column B is greater
Let the rectangle's width be w, so its length is 2w and its perimeter is 6w. The square's side length is 46w=23w. The rectangle's area is 2w2, while the square's area is 49w2, so Quantity B is greater.
Question 3
In triangle ABC,m∠A=50∘ and m∠B>m∠C.
Column A
Column B
m∠B
65∘
AThe quantity in Column A is greater
BThe quantity in Column B is greater
CThe two quantities are equal
DThe relationship cannot be determined from the information given
Show answer
Answer: A — The quantity in Column A is greater
Angles B and C sum to 180∘−50∘=130∘. If they were equal, each would be 65∘. Since m∠B>m∠C, angle B must be greater than 65∘, so Quantity A is greater.
Study on the fly is an independent study tool and is not affiliated with, sponsored by, or endorsed by any testing organization, school, or government body.
ISEE® and Independent School Entrance Examination® are registered trademarks of the Educational Records Bureau (ERB).
All practice questions and passages are original works created for Study on the fly and are not reproduced from any official test.