If one angle is half of its complementary angle, find that angle.

Each side of an equilateral triangle is 4 cm. What will be its area?

If the area of a circle, inscribed in a equilateral triangle is 4 π cm², then what is the area of the triangle?

If the ratio of the measurement of the four angles of a quadrilateral is 1: 2: 3: 4, then the measurement of its smallest angle is-

In ΔABC, ∠C=90° and D is a point on CB such that AD is the bisector of ∠A. If AC=5 cm and BC=12 cm, then what is the length of AD?

PQR is an equilateral triangle whose side is 10 cm . What is the value (in cm) of the inradius of triangle PQR ?

If the ratio of the heights of two identical triangles is 4: 9, find the ratio of the areas of the two triangles.

The largest and the second largest angles of a triangle are in the ratio of 3 : 2 respectively. The smallest angle is 20% of the sum of the rest two angles. What is the sum of the smallest and the second largest angles?