Question

Suppose you have a right triangle △DEF where ∠E is the right angle. If EF = 8 and DE = 10, which can be used to find ∠F?

A) Sine Rule

B) Cosine Rule

C) Tangent Rule

D) Pythagorean Theorem

Answer 1

To find angle F in the right triangle △DEF, you can use the Sine Rule. The Sine Rule states that for any triangle, the ratio of the length of a side to the sine of its opposite angle is constant.

Step-by-step explanation:

To find the measure of angle F in the right triangle △DEF, we can use the Sine Rule. The Sine Rule states that for any triangle, the ratio of the length of a side to the sine of its opposite angle is constant. In this case, we can use the Sine Rule to find the sine of angle F:

sin(F) = EF / DE

sin(F) = 8 / 10

sin(F) = 0.8

To find angle F, we can take the inverse sine (arcsine) of 0.8:

F = arcsin(0.8)

Using a scientific calculator, we can find that F is approximately 53.13 degrees.