Examples

Two of the angles in a triangle are and . How large is the third angle?

Is the triangle of the previous question acute, right-angled or obtuse?

How large is the angle in the above triangle?

What is the area of the above shape?

What is the perimeter of the above shape?

The area of the above sector is . What is the area of the colored part of the circle in square meters?

The area of the above sector can also be calculated with the following formula: where is the length of the arc corresponding to the sector, and is the radius of the circle. Using this formula, determine the radius of the circle in meters when the arc corresponding to the sector is long.

The height of the above cylinder is...

The height of the above square pyramid is...