Question

1. question 9. if the sine of an angle in a right triangle is 0.5, the cosine of the complementary angle is:

a) 0
b) 0.5
c) 1
d) 2

1. question 10. the pythagoras theorem can only be applied to:

a) right triangles.
b) acute triangles.
c) obtuse triangles.
d) equilateral triangles.

leave a comment for your parent/teacher in the box below:

Explanation:

Step1: Solve Question 9

Let the angle be $\theta$. We know $\sin\theta = 0.5$. The complementary angle is $90^\circ - \theta$. By co-function identity, $\cos(90^\circ - \theta) = \sin\theta$. Substitute $\sin\theta = 0.5$, so $\cos(90^\circ - \theta) = 0.5$.

Step2: Solve Question 10

Recall the definition of Pythagoras theorem: it states that in a triangle, the square of the hypotenuse equals the sum of squares of the other two sides. The hypotenuse is a side exclusive to right triangles, so the theorem only applies to them.

Answer:

1. b) 0.5
2. a) Right triangles.