First option. The inequality can be split into two separate inequalities.
first one no second one no third one no frouth no fifth yes last one no
ANSWER
C) Triangle
EXPLANATION
Solving a triangle is the process of calculating unknown side lengths or angle measures of a triangle if certain of the side lengths and/or angle measures are known.
We use the sine rule and cosine rule to find the missing sides and angles.
If the triangle has a right angle, then this is a special case, where we can use the trigonometric ratios and the Pythagoras theorem to find the unknown angles and sides.
