CIE Mathematics Paper-1: Specimen Questions 167 - 168 of 175
Question number: 167
Write in Short
The area of a square is 42.25 . Find length of one side of the square.
Here, formula for area of a square = where, a is side of square.
- So, here,
Question number: 168
Describe in Detail
In the diagram AC is the diameter of a circle, center O. The length of AC is 12 cm.
(a) Write down the size of angle ABC.
(b) Angle BAC = 40°. Calculate the length of BC.
(c) Calculate the area of the circle.
Here, AC is the diameter of a circle which is of 12 cm and O is center.
(a) Size of
Here, edge AC of triangle is diameter of the circle which will be diagonal of triangle ABC.
So, we can see in the figure, it is a right angled triangle, so
- The triangle formed by the diameter and the inscribed angle (triangle ABC above) is always a right triangle.
(b) Here, Angle BAC = 40° and length of AC is 12 cm.
So, using cosine formula of triangle:
(C) Area of circle = , where r = radius of circle.
So, here diameter AC = 12 cm, so radius = .
So, area of circle = .