Tricky Geometry Problems

Tricky Geometry Questions

Can you solve these tricky geometry problems? All of these can be solved using high school/GCSE mathematics and are great as stretching activities for high-achieving students.
Click on any image to view the walkthrough solution video on the DoingMaths YouTube channel.

We have an annulus with a 2ocm chord which is tangent to the inner circle. What is the area of the annulus?

We have an equilateral containing three identical circles of radius 4cm. What is the perimeter of the triangle?

We have an annulus with a 2ocm chord which is tangent to the inner circle. What is the area of the annulus?

We have an equilateral containing three identical circles of radius 4cm. What is the perimeter of the triangle?

What is the area of the circle inside the square?

An isosceles triangle inside a circle. What is the radius of the circle?

A circle containing perpendicular lines of length 5cm, 6cm and 4cm. What is the radius of the circle?

Three overlapping circles. What is the area of the blue region?

What is the area of the quarter circle containing a square of area 28cm^2?

We have two semi circles inside a larger quarter circle. What is the area of the blue region?