13 ABCDE is a regular pentagon with sides of length 10 cm.
a)
Calculate the area of triangle ACD.
Give your answer correct to 3 significant figures.​

If two angles of a triangle have equal measures and the third angle measures 90°, what are the angle measures of the triangle? a. 60°, 60°, 60° b. 45°, 90°, 90° c. 30°, 30°, 90° d. 45°, 45°, 90°